JP6936582B2 - Leaked radio wave detection device - Google Patents

Description

The present invention relates to a technique for detecting leaked radio waves from receiving equipment for satellite broadcasting, and in particular, leaks that can identify the presence or absence of leaked radio waves from receiving equipment for satellite broadcasting in a house and the position or direction of the leaked radio wave source. Regarding radio wave detection device.

The current satellite digital broadcasting (hereinafter abbreviated as "BS") currently transmits a satellite broadcasting signal of right-handed circular polarization together with 110-degree east longitude CS digital broadcasting (hereinafter abbreviated as "CS"), and is a parabolic antenna. It is possible to receive using a receiving antenna such as. Since right-handed circularly polarized light and left-handed circularly polarized light can be shared, in the future, if left-handed circularly polarized light is used, satellite broadcasting signals of, for example, different programs can be transmitted at the same frequency, and the frequency can be effectively used.

In addition, satellite broadcasting (BS / CS) uses radio waves in the 12 GHz band, and since the attenuation of the wiring in the house is large as it is, the satellite broadcasting signal received by the receiving antenna is abbreviated as an intermediate frequency signal (hereinafter, abbreviated as "IF signal"). ), And it is generally transmitted to the receiver in the house using a coaxial cable.

Currently, 1,032 MHz to 2,071 MHz are used as IF signals for satellite broadcasting (right-handed circularly polarized waves for BS / CS) using right-handed circularly polarized waves. 2,224 MHz to 3,224 MHz are specified as IF signals for satellite broadcasting using left-handed circularly polarized waves (left-handed circularly polarized waves for BS / CS), and will be used in the future (for example, non-patented). Reference 1).

In the current satellite broadcasting (BS / CS), a predetermined transmission control signal (TMCC signal) is multiplexed, and by first demodulating / decoding this TMCC signal, the satellite broadcasting signal of the main signal can be demodulated / decoded. (See, for example, Non-Patent Document 2). In addition, TMCC signals are also specified for advanced broadband satellite digital broadcasting (see, for example, Non-Patent Document 3).

In addition, an exclusive OR / XOR type phase comparator is provided in the satellite repeater in satellite broadcasting to detect and monitor the phase difference of the broadband modulated wave of each element of the array feeding section in the satellite repeater. (For example, see Non-Patent Document 4).

By the way, the frequency band of the IF signal for BS / CS left-handed circularly polarized waves is used by other wireless services such as mobile phones (LTE), wireless LAN, and WiMAX.

Therefore, when using a coaxial cable that transmits an IF signal for BS / CS left-handed circular polarization, considering the future IF signal for BS / CS left-handed circular polarization, BS / CS receiving equipment (boosters and distributors) Alternatively, it is important to adopt a coaxial cable connector or coaxial terminal, or the coaxial cable itself) with high shielding performance so that it can be shared while avoiding interference with other services.

For example, FIG. 7A shows a typical home broadcast radio wave receiving system 400. As shown in FIG. 7A, the IF signal of the satellite broadcast signal from the BS / CS receiving antenna 100 generally installed outside the house and the broadcast signal from the UHF receiving antenna 200 are mixed with the mixer 300. Is mixed and transmitted to the home broadcast radio wave receiving system 400 via the coaxial cable CL1.

In the home broadcast radio wave receiving system 400, the distributor 401 often inputs the signals mixed by the mixer 300 and distributes the signals to the coaxial terminals provided in various places via the coaxial cable. In the example shown in FIG. 7A, the distributor 401 and the four coaxial terminals 402a, 402b, 402c, 402d (collectively referred to as “coaxial terminal 402”) are connected by the respective coaxial cables CL2, CL3, CL4, and CL5. You are connected.

Further, each coaxial terminal may be directly connected to a television (TV) as a receiver, or may be connected to each coaxial terminal via a booster functioning as an amplification device. In the example shown in FIG. 7A, the coaxial terminal 402b and the booster 403 are connected by a coaxial cable CL6 (collectively referred to as “coaxial cable CL”), and the booster 403 is connected to the television as receivers 404a and 404b. (TV) is connected.

Generally, in a home broadcast radio wave receiving system, an F-type connector is used as a connector for a coaxial cable for satellite broadcasting in order to improve the shielding performance of preventing radio wave leakage.

However, for example, as shown in FIG. 7B, there is a poor formation of the coaxial cable CL that is difficult to see, a poor contact between the coaxial cable CL and the F-type connector FC, or a wall inside / outdoor that is difficult to see. If the coaxial terminal 402 has a poor connection, leaked radio waves that cause interference with other services may occur.

Further, for example, as shown in FIG. 7 (c), the shield material of the coaxial cable CL is hard to see inside the wall by using the metal fitting 4021 without using the F-type connector (or without utilizing the shielding performance of the F-type connector). The coaxial terminal 402 of the old connection method, in which the core wire of the coaxial cable CL is exposed and connected by the core wire connection part 4022, or the distributor 401 or booster 403 of the same old connection method, which is connected to the ground by the coaxial terminal 402 on the outdoor side. If there is a device such as (hereinafter abbreviated as "old device"), leaked radio waves that cause interference with other services may occur. In particular, it is known that the old equipment that does not use the F-type connector has a shielding performance that is about 30 to 40 dB lower than that of the equipment that makes the best use of the shielding performance of the F-type connector.

Therefore, in order to maintain high shielding performance in the entire home broadcast radio wave receiving system, it is necessary to identify the position of the leaked radio wave source and replace or repair the equipment of the leaked radio wave source.

That is, with respect to the home broadcast radio wave receiving system, a leaked radio wave detecting device that can identify the presence or absence of leaked radio waves in the receiving equipment for satellite broadcasting and the position or direction of the leaked radio wave source is required.

In the conventional technique, the explorer has an antenna with a sharp directionalness and detects it while visually observing the waveform of the spectrum analyzer, but the IF signal of satellite broadcasting is not an unmodulated signal (CW). Since it is a digitally modulated signal, it is difficult to detect leaked radio waves related to the IF signal of satellite broadcasting by this conventional technique.

For television broadcasting, CATV broadcasting, and other public or private transmission / communication lines, the leaked radio waves of the coaxial cable laid elevated are received by the antenna attached to the tip of the pole to search for the broken part. The technique is known (see, for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2003-215195

"Receiver standard for advanced broadband satellite digital broadcasting (desired specification) ARIB STD-B63 1.6 version", Association of Radio Industries and Businesses (ARIB), revised on December 9, 2016 "Satellite Digital Broadcast Transmission System Standard ARIB STD-B20 3.0 Version", Association of Radio Industries and Businesses (ARIB), revised on May 31, 2001 "Transmission method for advanced broadband satellite digital broadcasting (ISDB-S3) Standard ARIB STD-B44 2.1 version", Association of Radio Industries and Businesses (ARIB), revised on March 25, 2016 Nagasaka et al., “Study of Phase Detection Method for 21GHz Band Broadcasting Satellites Equipped with Array Feeding Reflector Antenna”, Institute of Electronics, Information and Communication Engineers, Institute of Electronics, Information and Communication Engineers, Vol.113, no.436, SAT2013-55, 2014 , p.29-34, February 2014

As described above, with respect to the home broadcast radio wave receiving system, a leaked radio wave detection device that can identify the presence or absence of leaked radio waves in the receiving equipment for satellite broadcasting and the position or direction of the leaked radio wave source is required. In the conventional technique, the explorer has an antenna with a sharp directionalness and detects it while visually observing the waveform of the spectrum analyzer, but the IF signal of satellite broadcasting is not an unmodulated signal (CW). Since it is a digitally modulated signal, it is difficult to detect leaked radio waves related to the IF signal of satellite broadcasting by this conventional technique.

On the other hand, the technique disclosed in Patent Document 1 is adapted to search for leaked radio waves of an elevated coaxial cable. However, even if the technique disclosed in Patent Document 1 is applied to the search for leaked radio waves in the home broadcast radio wave receiving system, the burden on the explorer is heavy, and a coaxial cable or a coaxial cable is used in a place that cannot be seen by the home broadcast radio wave receiving system. Since each terminal or a device connecting these terminals is arranged, it is difficult to search with high accuracy.

In view of the above problems, the present invention easily and highly accurately detects the presence or absence of leaked radio waves in the receiving equipment for satellite broadcasting in the home broadcasting radio wave receiving system, and the position or direction of the leaked radio wave source. The purpose is to provide a radio wave detection device.

The leaked radio wave detection device of the present invention is a leaked radio wave detection device that can identify the presence or absence of leaked radio waves in a receiving facility for satellite broadcasting in a house and the position or direction of the leaked radio wave source, and is a device for detecting leaked radio waves at predetermined antenna intervals. A pair of receiving antennas for detecting leaked radio waves and a pair of receiving antennas for detecting leaked radio waves, which have the same electrical characteristics and have reception sensitivity at least in the intermediate frequency signal band of satellite broadcasting, received waves. The first received signal and the second received signal of the frequency of the leaked radio wave to be detected are phase-compared by exclusive logical sum calculation, and the voltage signal corresponding to the phase difference between the first received signal and the second received signal is obtained. The phase difference is calculated based on the phase difference detection signal generated as the phase difference detection signal and the phase difference detection signal, and the leaked radio wave of the detection target is used by the wavelength of the leaked radio wave of the detection target and the value of the antenna interval. A signal processing unit for specifying the direction of the leaked radio wave source is provided , and the phase comparator inputs the first received signal and the second received signal, and inputs the first received signal and the second received signal. An exclusive logic sum comparison circuit that generates an analog voltage signal whose phase is compared by an exclusive logic sum operation via a log amplifier type amplification circuit that compresses the amplitude of each of the above, and an analog obtained from the exclusive logic sum comparison circuit. An integrator circuit that performs low-pass filter processing on a voltage signal, and an amplification circuit that generates the phase difference detection signal by setting an analog voltage signal that has been subjected to low-pass filter processing obtained from the integrator circuit into a desired voltage range. characterized by Rukoto equipped with.

Further, in the leaked radio wave detecting device of the present invention, the pair of receiving antennas for detecting leaked radio waves each have a receiving central axis showing directivity in the same direction, and in a plane direction with the receiving central axis as a normal line. It is characterized in that it is configured to have reception sensitivity at least in the band of the intermediate frequency signal of satellite broadcasting.

Further, in the leaked radio wave detection device of the present invention, whether the signal processing unit refers to a voltage / phase difference conversion table previously held in order to convert the voltage value into the phase difference based on the phase difference detection signal. , Or a means for calculating the phase difference by an arithmetic expression corresponding to the voltage / phase difference conversion table.

Further, in the leaked radio wave detection device of the present invention, the phase comparator indicates that there is no leaked radio wave when both the first received signal and the second received signal to be compared are equal to or less than a predetermined threshold value. It is characterized in that a voltage value of zero is output as the phase difference detection signal.

Further, in the leaked radio wave detection device of the present invention, a plurality of sets are provided with the pair of leaked radio wave detection receiving antennas and the phase comparator as one set, and each set of the pair of leaked radio wave detection receiving antennas is provided. By arranging them in different directions and corresponding to the multidimensional surface directions, the signal processing unit simultaneously detects the presence or absence of the leaked radio wave and the position or direction of the leaked radio wave source with respect to the multidimensional surface direction. It is characterized by providing means for doing so.

Further, the leaked radio wave detecting device of the present invention is a leaked radio wave detecting device that can identify the presence or absence of leaked radio waves in the receiving equipment for satellite broadcasting in the house and the position or direction of the leaked radio wave source, and is predetermined to each other. Received by each of the pair of receiving antennas for detecting leaked radio waves and the pair of receiving antennas for detecting leaked radio waves, which are arranged at antenna intervals and have equal electrical characteristics and have reception sensitivity at least in the intermediate frequency signal band of satellite broadcasting. Phase comparison is performed for the first received signal and the second received signal of the frequency of the leaked radio wave to be detected by an exclusive logical sum calculation, and the voltage corresponding to the phase difference between the first received signal and the second received signal. The phase difference is calculated based on the phase difference detection signal and a phase comparator that generates a signal as a phase difference detection signal, and the detection target uses the wavelength of the leaked radio wave to be detected and the value of the antenna interval. It is equipped with a signal processing unit that identifies the direction of the leaked radio wave source of the leaked radio wave, and has an intermediate frequency of the satellite broadcast received via the pair of receiving antennas for detecting the leaked radio wave prior to the detection of the leaked radio wave. The predetermined transmission control signal of each channel in the signal band is demoted, the reception quality of each channel is measured, and the antenna of the channel having the highest reception quality is automatically set to the antenna of the detection target of the leaked radio wave for the signal processing unit. It is characterized by further including a channel selection evaluation unit to be set.

According to the present invention, it is easy to detect the presence or absence of leaked radio waves in the receiving equipment that handles IF signals transmitted as digitally modulated signals in satellite broadcasting in satellite broadcasting by the home broadcasting radio wave receiving system, and the position or direction of the leaked radio wave source. And it can be done with high accuracy.

More preferably, human labor saving and automation can be achieved by arranging a plurality of receiving antennas for detecting leaked radio waves from multiple surfaces. More preferably, by demodulating the TMCC signal in satellite broadcasting and selecting (tuning) the wavelength based on the reception quality, it is possible to save human labor and search for leaked radio waves with higher accuracy.

It is a block diagram which shows the schematic structure of the leakage radio wave detection device of 1st Embodiment by this invention. It is a block diagram which shows the schematic structure of the phase comparator in the leakage radio wave detection device of 1st Embodiment by this invention. It is a figure which illustrates the voltage / phase difference conversion table in the leakage radio wave detection apparatus of 1st Embodiment by this invention. It is a block diagram which shows the schematic structure of the leakage radio wave detection device of 2nd Embodiment by this invention. It is a block diagram which shows the schematic structure of the leakage radio wave detection device of 3rd Embodiment by this invention. It is a flowchart which shows the process of the channel selection evaluation part in the leakage radio wave detection apparatus of 3rd Embodiment by this invention. (A) is a block diagram showing a schematic configuration of a typical home broadcast radio wave receiving system, and (b) and (c) are diagrams illustrating devices serving as leaked radio wave sources, respectively.

Hereinafter, the leaked radio wave detection device 1 of each embodiment according to the present invention will be described with reference to the drawings. The leaked radio wave detection device 1 of each embodiment described below includes the presence or absence of leaked radio waves in the receiving equipment for satellite broadcasting in the home, such as the home broadcast radio wave receiving system 400 illustrated in FIG. 7, and the position of the leaked radio wave source. Alternatively, it is a device that can identify the direction.

[First Embodiment]
FIG. 1 shows a block diagram showing a schematic configuration of the leaked radio wave detection device 1 according to the first embodiment of the present invention. The leaked radio wave detection device 1 includes a pair of receiving antennas for detecting leaked radio waves (first antenna section 2a and second antenna section 2b), a pair of bandpass filters (BPF) 3a and 3b, a phase comparator 4, and the like. It includes a signal processing unit 5 and a display unit 6.

The first antenna unit 2a and the second antenna unit 2b are arranged at a predetermined antenna spacing d and have equal electrical characteristics, and each has a reception center axis showing directivity in the same direction, and the reception center axis is normal. It has reception sensitivity in the band of the IF signal of satellite broadcasting in the plane direction (in the range of −90 degrees to 90 degrees with respect to the reception center axis). Then, each of the first antenna portion 2a and the second antenna portion 2b receives the IF signals for right-handed and left-handed circularly polarized waves of BS / CS, and each of the received IF signals is a pair of bandpass filters. (BPF) Output to 3a and 3b.

Here, as shown in FIG. 1, assuming that the direction of the leaked radio wave of the IF signal arriving from the leaked radio wave source is an angle θ with respect to the reception center axis of each of the first antenna portion 2a and the second antenna portion 2b. The leaked radio wave arriving at the second antenna portion 2b propagates a long distance by d · sinθ with respect to the leaked radio wave arriving at the first antenna portion 2a.

Assuming that the wavelength of the leaked radio wave of the IF signal is λ, the phase difference (degree) of the leaked radio wave received by the first antenna portion 2a and the second antenna portion 2b is 360 × (d · sinθ) / λ. .. For example, if the distance of d · sinθ is 0.5λ, the phase difference is 180 degrees.

The pair of bandpass filters (BPFs) 3a and 3b are bandpass filters that pass only signals of a desired frequency with the same bandwidth. The BPF3a outputs the band-limited first received signal to the phase comparator 4 with respect to the IF signal from the first antenna unit 2a, and the BPF3b outputs the band-limited second received signal to the IF signal from the second antenna unit 2b. Output to the phase comparator 4.

However, when the first antenna portion 2a and the second antenna portion 2b have a frequency characteristic of receiving only the signal of the desired frequency (IF signal to be detected), or when the first antenna portion 2a and the second antenna portion 2b are received. If it has the same filter function as BPF3a and BPF3b, respectively, it is not necessary to provide BPF3a and BPF3b again.

The desired frequency is the frequency of the leaked radio wave to be detected, and the wavelength λ of the frequency of the leaked radio wave to be detected is set in advance in the signal processing unit 5.

The phase comparator 4 performs phase comparison between the input first received signal from the first antenna unit 2a and the second received signal from the second antenna unit 2b by an exclusive logical sum calculation, and performs a phase comparison with the first received signal. A voltage signal corresponding to the phase difference between the second received signal and the second received signal is output to the signal processing unit 5 as a phase difference detection signal. The phase comparator 4 is configured by an exclusive OR type analog phase comparator as shown in FIG. As shown in FIG. 2, the phase comparator 4 includes an exclusive OR comparison circuit 41, an integrator circuit 42, and an amplifier circuit 43.

The exclusive logic sum comparison circuit 41 inputs the first received signal from the first antenna unit 2a and the second received signal from the second antenna unit 2b, and the first received signal and the second received signal are respectively. On the other hand, an analog voltage signal whose phase is compared by an exclusive logical sum operation is generated through a log amplifier type amplifier circuit (not shown) that compresses the amplitude, and is output to the integrating circuit 42.

The amplifier circuit 42 is composed of a low-pass filter processing circuit for removing high-pass components unnecessary for detecting the phase difference, and low-pass filter processing is performed on the analog voltage signal obtained from the exclusive logic sum comparison circuit 41. Is applied and output to the amplifier circuit 43.

The amplifier circuit 43 amplifies the input voltage signal to a desired voltage range, whereby the voltage signal corresponding to the phase difference between the first received signal and the second received signal is used as the phase difference detection signal in the signal processing unit 5. Output.

As described above, unlike the spectrum analyzer which can measure only the phase measurement of the unmodulated signal, the phase comparator 4 can perform the phase comparison of the digitally modulated signal because the phase is compared by the exclusive logical sum operation, and the phase difference is detected. The phase difference can be expressed by the voltage value within a predetermined scale by the signal.

FIG. 3 shows actual measurement values of the detection characteristics of the phase comparator 4. Due to the structure of the exclusive OR type phase comparator constituting the phase comparator 4, as shown in FIG. 3, the phase difference is detected between the range of −90 degrees to 90 degrees and the range of 90 degrees to 270 degrees. The result is an equal voltage. Therefore, in mounting the phase comparator 4, by using the phase difference in the range of −90 degrees to 90 degrees, the phase comparator 4 is substantially linear between the voltage value of the phase difference detection signal and the phase difference to be detected. It functions as a phase difference detection sensor that can obtain the relationship of. In general, the better the linearity of the output value with respect to the input value, the higher the detection accuracy of the sensor. In FIG. 3, the phase difference detection with high accuracy is obtained by configuring the phase comparator 4 with the exclusive OR type phase comparator. Indicates that is possible.

With reference to FIG. 1, the signal processing unit 5 includes a phase difference detection unit 51, a voltage / phase difference conversion table storage unit 52, and a leaked radio wave source direction calculation unit 53.

The signal processing unit 5 includes a voltage / phase difference conversion table storage unit 52 that stores and holds the voltage / phase difference conversion table, and also has a voltage / phase difference with the phase difference detection signal from the phase comparator 4 before the detection operation. The data of the initial correction (calibration) associated with the conversion table and the data of the set value of the wavelength λ of the leaked radio wave of the IF signal to be detected and the antenna interval d are stored in advance in a storage unit (not shown).

The phase difference detection unit 51 refers to the voltage / phase difference conversion table stored in the voltage / phase difference conversion table storage unit 52 based on the phase difference detection signal obtained from the phase comparison device 4, and refers to the first antenna unit. The phase difference (degree) of the leaked radio wave received by the 2a and the second antenna unit 2b is calculated and output to the leaked radio wave source direction calculation unit 53.

The voltage / phase difference conversion table is a table showing voltage values in the range of −90 degrees to 90 degrees for the phase difference shown in FIG. 3, and the phase difference detection unit 51 corresponds to the voltage value of the phase difference detection signal. Calculate the phase difference. The phase difference detection unit 51 performs initial correction (calibration) for associating the phase difference detection signal from the phase comparator 4 with the voltage / phase difference conversion table before the detection operation.

The leaked radio wave source direction calculation unit 53 stores the wavelength λ of the leaked radio wave of the IF signal to be detected and the antenna interval d, which are set in advance, in a storage unit (not shown), and uses the wavelength λ and the antenna interval d to store the wavelength λ and the antenna interval d. The direction θ of the leaked radio wave source with respect to the reception central axis indicating the directivity of the first antenna unit 2a and the second antenna unit 2b is calculated and output to the display unit 6.

Using the wavelength λ of the leaked radio wave of the IF signal to be detected and the antenna interval d, the phase difference (degree) of the leaked radio wave received by the first antenna section 2a and the second antenna section 2b is 360 × (degree). Since d · sin θ) / λ, the leaked radio wave source direction calculation unit 53 can calculate the direction θ of the leaked radio wave source.

The antenna interval d can be determined by the assumed range of the direction θ of the leaked radio wave to be detected and the range of the phase comparison of the phase comparator 4.

In this example, the direction θ of the leaked radio wave to be detected is −90 degrees <θ <90 degrees, and the phase difference is −90 degrees <360 × (d · sin θ) / λ <90 degrees.

Therefore, the antenna spacing d may be λ / 2 or less because of the relationship of −λ / 2 <d · sin θ <λ / 2 and −90 degrees <θ <90 degrees.

The display unit 6 displays the direction θ of the leaked radio wave to be detected based on the calculation result of the signal processing unit 5. Since the display unit 6 may be an external terminal such as a smartphone, the leaked radio wave detection device 1 provides an output interface to the external terminal capable of displaying the direction θ of the leaked radio wave to be detected instead of providing the display unit 6. It can be configured to be provided.

As the pair of receiving antennas for detecting leaked radio waves (first antenna portion 2a and second antenna portion 2b), if an antenna that can be mounted on a printed substrate such as a microstrip antenna is used, the first antenna portion 2a and the second antenna portion are used. 2b can be mounted on one antenna board to reduce the size and make the antenna characteristics uniform.

In the input stage of the exclusive OR comparison circuit 41 shown in FIG. 2, the phase comparator 4 sets zero as the voltage value when both the first received signal and the second received signal are equal to or less than a predetermined threshold value. It can be configured to output and to make a determination assuming that there is no leaked radio wave. When the output voltage value of the exclusive OR comparison circuit 41 is zero, the output voltage value of the phase comparator 4 is also zero. When the output voltage value of the phase comparator 4 is zero, it also deviates from the characteristic result shown in FIG. 3 (that is, the corresponding voltage / phase difference conversion table), so the signal processing unit 5 determines that there is no leaked radio wave. That fact can be output to the display unit 6. However, as described above, when the output voltage (phase difference detection signal) of the phase comparator 4 is within the characteristic result shown in FIG. 3 (that is, the corresponding voltage / phase difference conversion table), it is determined that there is a leaked radio wave. , The phase comparison of the first received signal and the second received signal is performed.

In the present embodiment, the signal of the frequency to be detected is an IF signal for BS / CS right-handed circularly polarized waves or an IF signal for BS / CS left-handed circularly polarized waves, but for BS / CS right-handed circularly polarized waves. By detecting radio wave leakage only with the IF signal of, it is possible to infer the radio wave leakage of the IF signal for BS / CS left-handed circularly polarized light. The frequency of the IF signal for BS / CS right-handed circularly polarized waves is relatively lower than that of the IF signal for left-handed circularly polarized waves. Since the satellite broadcasting service is already provided by the above, the accuracy will be further improved by detecting the radio wave leakage only by the IF signal for BS / CS right-handed circularly polarized light.

As described above, according to the leaked radio wave detection device 1 of the first embodiment, in the home broadcast radio wave receiving system, a pair of receiving antennas for detecting leaked radio waves (first antenna unit 2a and second antenna unit 2b) are provided. Presence or absence of leaked radio waves from receiving equipment that handles IF signals transmitted as digitally modulated signals in satellite broadcasting in satellite broadcasting in the one-dimensional plane direction (range of -90 degrees to 90 degrees with respect to the central axis of reception). And the position or direction of the leaked radio wave source can be easily detected and highly accurately detected. When detecting leaked radio waves in a multidimensional plane direction (range of -90 degrees to 90 degrees with respect to the receiving center axis), a pair of receiving antennas for detecting leaked radio waves (first) in the plane direction that the operator wants to detect. The antenna portion 2a and the second antenna portion 2b) may be directed.

[Second Embodiment]
FIG. 4 shows a block diagram showing a schematic configuration of the leaked radio wave detection device 1 according to the second embodiment of the present invention. The same reference numbers are given to the components similar to those in FIG. In the first embodiment, it is not possible to detect leaked radio waves at once in a plurality of dimensional plane directions (range of −90 degrees to 90 degrees with respect to the reception center axis), but in the second embodiment, this is possible. This is an example of

The leaked radio wave detection device 1 of the second embodiment has a pair of receiving antennas (first antenna section 2a and second antenna section 2b) for detecting leaked radio waves, a pair of bandpass filters (BPF) 3a and 3b, and a phase. In this example, a functional unit that generates a first phase difference detection signal for detecting leaked radio waves in the horizontal direction and a pair of receiving antennas for detecting leaked radio waves (third antenna unit 2c and a third antenna unit 2c) are combined with a comparator 4a. 4 Antenna unit 2d), a pair of band path filters (BPF) 3c and 3d, and a phase comparator 4b are used as a set to generate a second phase difference detection signal for detecting leaked radio waves in the vertical direction in this example. It includes a functional unit, a signal processing unit 5, and a display unit 6.

The pair of receiving antennas for detecting leaked radio waves (first antenna unit 2a and second antenna unit 2b), the pair of bandpass filters (BPF) 3a and 3b, and the phase comparator 4a in the second embodiment are each the first. It is configured in the same manner as the pair of receiving antennas for detecting leaked radio waves (first antenna unit 2a and second antenna unit 2b), the pair of bandpass filters (BPF) 3a and 3b, and the phase comparator 4 in the embodiment. The first antenna portion 2a and the second antenna portion 2b have reception sensitivity in the horizontal direction. The phase comparator 4a generates a first phase difference detection signal that represents the phase difference between the first received signal obtained from the first antenna unit 2a and the second received signal obtained from the second antenna unit 2b as a voltage value. Output to the signal processing unit 5.

Further, the pair of receiving antennas for detecting leaked radio waves (third antenna section 2c and fourth antenna section 2d), the pair of bandpass filters (BPF) 3c and 3d, and the phase comparator 4b in the second embodiment are respectively. It is configured in the same manner as the pair of receiving antennas for detecting leaked radio waves (first antenna unit 2a and second antenna unit 2b), the pair of bandpass filters (BPF) 3a and 3b, and the phase comparator 4 in the first embodiment. NS. The third antenna portion 2c and the fourth antenna portion 2d have reception sensitivity in the vertical direction. The phase comparator 4b generates a second phase difference detection signal that represents the phase difference between the third received signal obtained from the third antenna unit 2c and the fourth received signal obtained from the fourth antenna unit 2d as a voltage value. Output to the signal processing unit 5.

That is, in the second embodiment, a plurality of sets of receiving antennas for detecting leaked radio waves are arranged in different directions to enable detection of leaked radio waves in a plurality of dimensional plane directions.

However, when the first antenna portion 2a and the second antenna portion 2b, or the third antenna portion 2c and the fourth antenna portion 2d have a frequency characteristic of receiving only a signal of a desired frequency (IF signal to be detected). If the first antenna portion 2a and the second antenna portion 2b themselves have the same filter functions as BPF3a, BPF3b, or BPF3c, BPF3d, it is not necessary to provide BPF3a, BPF3b, or BPF3c, BPF3d again.

The signal processing unit 5 includes phase difference detection units 51a and 51b, a voltage / phase difference conversion table storage unit 52, and a leakage radio wave source direction calculation unit 53a and 53b.

As in the first embodiment, the signal processing unit 5 includes a voltage / phase difference conversion table storage unit 52 that stores and holds the voltage / phase difference conversion table, and also from the phase comparators 4a and 4b before the detection operation. Initial correction (calibration) data that associates the first and second phase difference detection signals with the voltage / phase difference conversion table, and the set values of the leaked radio wave wavelength λ and antenna interval d of the IF signal to be detected. Data is stored in advance in a storage unit (not shown).

The phase difference detection units 51a and 51b perform voltage / phase difference conversion stored in the voltage / phase difference conversion table storage unit 52 based on the first and second phase difference detection signals obtained from the phase comparators 4a and 4b, respectively. With reference to the table, the phase difference (degree) of the leaked radio wave received by the first antenna section 2a and the second antenna section 2b, respectively, and the leaked radio wave received by the third antenna section 2c and the fourth antenna section 2d, respectively. The phase difference (degrees) of the above is calculated and output to the leakage radio wave source direction calculation units 53a and 53b, respectively.

Similar to the first embodiment, the voltage / phase difference conversion table is a table showing voltage values in the range of −90 degrees to 90 degrees for the phase difference shown in FIG. 3, and the phase difference detecting units 51a and 51b are respectively. The corresponding phase difference is calculated from the voltage values of the first and second phase difference detection signals. In the phase difference detection units 51a and 51b, initial correction (calibration) for associating the first and second phase difference detection signals from the phase comparators 4a and 4b with the voltage / phase difference conversion table is performed before the detection operation. Will be.

The leaked radio wave source direction calculation units 53a and 53b store and hold the wavelength λ and the antenna interval d of the leaked radio wave of the IF signal to be detected, which are set in advance, in a storage unit (not shown), and store the wavelength λ and the antenna interval d in a storage unit (not shown). In use, the direction θa of the leaked radio wave source with respect to the reception center axis indicating the directionality of the first antenna unit 2a and the second antenna unit 2b, and the reception center indicating the directionality of the third antenna unit 2c and the fourth antenna unit 2d. The direction θb of the leaked radio wave source with respect to the axis is calculated and output to the display unit 6.

The display unit 6 simultaneously displays the directions θa and θb of the leaked radio wave to be detected based on the calculation result of the signal processing unit 5. Since the display unit 6 may be an external terminal such as a smartphone, the leaked radio wave detection device 1 is for an external terminal capable of simultaneously displaying the directions θa and θb of the leaked radio wave to be detected instead of providing the display unit 6. It can be configured to provide an output interface.

As described above, in the second embodiment, the leaked radio wave can be detected at once in the two-dimensional plane direction. Then, if a pair of receiving antennas for detecting leaked radio waves are arranged in a six-dimensional plane direction, detection in all directions is possible. In addition to the configuration in which detection is performed in all directions at once, a configuration in which detection is performed by switching a predetermined direction is also possible.

As described above, according to the leaked radio wave detecting device 1 of the second embodiment, all the actions and effects of the leaked radio wave detecting device 1 of the first embodiment are included, and the leaked radio wave is generated in a plurality of dimensional plane directions. Detection can be done at once.

[Third Embodiment]
FIG. 5 shows a block diagram showing a schematic configuration of the leaked radio wave detection device 1 according to the third embodiment of the present invention. The same reference numbers are given to the components similar to those in FIG. In the first and second embodiments, an example in which the wavelength to be detected is set in advance has been described, but the BS / CS-IF band is as wide as 1032 to 3224 MHz (ARIB STD-B63), and the wavelength is 9 cm to 29 cm. The leaked radio wave is detected by setting any of the wavelength range (that is, the channel range). On the other hand, the intensity of the leaked radio wave for each channel (frequency) differs depending on the receiving equipment. Therefore, in order to detect the leaked radio wave with higher accuracy in the first and second embodiments, it is necessary to set the wavelength while changing the wavelength that the operator wants to detect.

In the third embodiment, prior to the detection of the leaked radio wave, a predetermined transmission control signal (TMCC signal) of each channel in the band of the IF signal in the BS / CS received via the pair of receiving antennas for detecting the leaked radio wave. ) Is demodulated to measure the reception quality of each channel, and the signal processing unit 5 is configured to automatically set the wavelength of the channel with the highest reception quality to the wavelength to be detected of the leaked radio wave.

Since the TMCC signal employs a modulation method having a low required C / N and being resistant to noise, it is most suitable for specifying a channel for determining a wavelength to be detected prior to detecting a leaked radio wave.

The leaked radio wave detection device 1 of the third embodiment shown in FIG. 5 includes a pair of receiving antennas (first antenna section 2a and second antenna section 2b) for detecting leaked radio waves, which are configured in the same manner as in the first embodiment. It includes a pair of bandpass filters (BPF) 3a and 3b, a phase comparator 4, a signal processing unit 5, a display unit 6, distributors 7a and 7b, and a channel selection evaluation unit 8.

Each operation of the pair of receiving antennas for detecting leaked radio waves (first antenna portion 2a and second antenna portion 2b), the pair of bandpass filters (BPF) 3a and 3b, and the phase comparator 4 is the same as that of the first embodiment. The same applies, and the description thereof will be omitted.

The distributors 7a and 7b phase the first received signal obtained from the first antenna unit 2a and the second received signal obtained from the second antenna unit 2b through the pair of bandpass filters (BPF) 3a and 3b, respectively. It is output to the comparator 4 and output to the channel selection evaluation unit 8.

The channel selection evaluation unit 8 is a functional unit that operates prior to detecting leaked radio waves, and is a switch 81, a frequency selection unit 82, an orthogonal detector 83, a TMCC demodulation unit 84, a signal determination unit 85, a control unit 86, and A storage unit 87 is provided.

The operation of the channel selection evaluation unit 8 will be described with reference to FIG.

First, the channel selection evaluation unit 8 controls the BPF3a and 3b to synchronize the BPF3a and 3b with a signal having a frequency corresponding to one reception channel in the BS / CS-IF band 1032 to 3224 MHz (frequency). (Synchronization setting signal) is set, and a channel selection control signal for selecting a reception frequency corresponding to the one reception channel is set in the frequency selection unit 82 (step S1).

Subsequently, the channel selection evaluation unit 8 controls the first received signal from the first antenna unit 2a and the second received signal from the second antenna unit 2b obtained from the distributors 7a and 7b under the control of the control unit 86. The switching device 81 that inputs and switches and outputs is selected and set by the antenna selection signal so that the first reception signal from the first antenna unit 2a is output to the frequency selection unit 82 (step S2).

The frequency selection unit 82 outputs the first reception signal from the first antenna unit 2a at the reception frequency corresponding to the one reception channel to the orthogonal detector 83.

The orthogonal detector 83 has an IQ baseband signal having an in-phase component (I) and an orthogonal component (Q) with respect to the first received signal (digitally modulated signal) from the first antenna unit 2a at the reception frequency corresponding to the one receiving channel. Is generated and output to the TMCC demodulation unit 84.

The TMCC demodulation unit 84 extracts the TMCC signal from the IQ baseband signal, demodulates it, and outputs it to the signal determination unit 85.

The signal determination unit 85 measures the error rate of the TMCC signal and outputs the reception quality information indicating the error rate to the control unit 86 (step S3).

Subsequently, the channel selection evaluation unit 8 stores the evaluation result (reception quality information) regarding the first reception signal from the first antenna unit 2a in the storage unit 87 in association with the one reception channel under the control of the control unit 86. Save (step S4).

Subsequently, the channel selection evaluation unit 8 selectively sets the switch 81 to output the second reception signal from the second antenna unit 2b to the frequency selection unit 82 under the control of the control unit 86 by the antenna selection signal. (Step S5).

The frequency selection unit 82 outputs the second reception signal from the second antenna unit 2b at the reception frequency corresponding to the one reception channel to the orthogonal detector 83, and outputs the orthogonal detector 83, the TMCC demodulation unit 84, and the signal determination unit. After passing through 85, the error rate of the TMCC signal is measured, and the reception quality information thereof is output to the control unit 86 (step S6).

Subsequently, the channel selection evaluation unit 8 stores the evaluation result (reception quality information) regarding the second reception signal from the second antenna unit 2b in the storage unit 87 in association with the one reception channel under the control of the control unit 86. Save (step S7).

Subsequently, the channel selection evaluation unit 8 controls the evaluation result (reception) regarding the first reception signal from the first antenna unit 2a for all the reception channels in the BS / CS-IF band 1032 to 3224 MHz under the control of the control unit 86. It is repeated until the evaluation result (reception quality information) regarding the second reception signal from the second antenna unit 2b (quality information) is obtained (step S8).

The channel selection evaluation unit 8 evaluates the evaluation result (reception quality information) regarding the first reception signal from the first antenna unit 2a and the evaluation result (reception quality) regarding the second reception signal from the second antenna unit 2b for all the reception channels. When the information) is obtained, the evaluation results (reception quality information) of all the reception channels are read out from the storage unit 87 (step S9) under the control of the control unit 86, and the error rates of the measured TMCC signals in each reception quality information are compared. Then (step S10), the channel having the smallest error rate value is determined (step S11).

Finally, the channel selection evaluation unit 8 is set in the leaked radio wave source direction calculation unit 53 in the signal processing unit 5 so that the wavelength corresponding to the determined reception channel is detected by the leaked radio wave under the control of the control unit 86. (Step S12).

After that, the signal processing unit 5 uses the wavelength λ set by the channel selection evaluation unit 8 to determine the presence or absence of leaked radio waves from the receiving equipment for satellite broadcasting in the house and the leaked radio wave source, as in the first embodiment. Detects the position or direction so that it can be specified.

The channel selection evaluation unit 8 is configured as a calibration function that operates when the power of the leaked radio wave detection device 1 is turned on or when the operator specifies it, and the wavelength λ set in the signal processing unit 5 is usually maintained. ..

The leaked radio wave detection device 1 of the third embodiment shown in FIG. 4 illustrates a modification from the first embodiment, but detects leaked radio waves in a plurality of dimensional plane directions as in the second embodiment. It can also be configured to be performed all at once.

As described above, the leaked radio wave detection device 1 of the third embodiment includes all the actions and effects of the leaked radio wave detection device 1 of the first or second embodiment, and prior to the detection of the leaked radio wave. By demodulating the TMCC signal in BS / CS and selecting the channel based on the reception quality, the wavelength to be detected can be automatically set within the wavelength range (that is, the channel range), which is a burden on the operator. It is possible to detect leaked radio waves with higher accuracy.

The present invention is not limited to the examples of the above-described embodiments, but is limited only by the description of the scope of claims. For example, an example of mainly targeting the detection of leaked radio waves of the IF signal of the current satellite broadcasting (BS / CS) has been described, but the leaked radio wave detecting device 1 according to the present invention is an IF signal of an advanced broadband satellite digital broadcasting. It can also be used to detect leaked radio waves in signals in frequency bands where there is a risk of interference with other services, such as detection of leaked radio waves.

Further, in the above-described example of the embodiment, in order to improve the accuracy, the pair of receiving antennas for detecting leaked radio waves each have a receiving central axis showing directivity in the same direction, and the receiving central axis is defined as a normal. Although it was explained that it is configured to have reception sensitivity at least in the band of the intermediate frequency signal of satellite broadcasting in the direction of the plane, strictness is required for the antenna arrangement of the receiving antennas for detecting a pair of leaked radio waves. Instead, the calibration function can absorb the error.

Further, in the example of the above-described embodiment, in order to improve the accuracy, the voltage / phase difference conversion table held in advance for converting the voltage value into the phase difference based on the phase difference detection signal is referred to. Although the example of calculating the phase difference has been described, the phase difference can also be calculated by using the calculation formula corresponding to the voltage / phase difference conversion table for the voltage value of the phase difference detection signal.

According to the present invention, the presence or absence of leaked radio waves in the receiving equipment and the position or direction of the leaked radio wave source can be easily and accurately detected, so that the signal is transmitted as a digitally modulated signal in satellite broadcasting in satellite broadcasting. It is useful for detecting leaked radio waves in home broadcast radio wave receiving systems that handle IF signals.

1 Leakage radio wave detection device 2a 1st antenna part 2b 2nd antenna part 2c 3rd antenna part 2d 4th antenna part 3a, 3b, 3c, 3d Bandpass filter (BPF)
4,4a, 4b Phase comparator 5 Signal processing unit 6 Display unit 7a, 7b Distributor 8 Channel selection evaluation unit 41 Exclusive logical sum comparison circuit 42 Integrator circuit 43 Amplifier circuit 51, 51a, 51b Phase difference detector 52 Voltage Phase difference conversion table storage unit 53, 53a, 53b Leakage radio wave source direction calculation unit 81 Switcher 82 Frequency selection unit 83 Orthogonal detector 84 TMCC demodulation unit 85 Signal judgment unit 86 Control unit 87 Storage unit 100 BS / CS receiving antenna 200 UHF antenna 300 Mixer 400 Home broadcast radio wave reception system 401 Distributor 402, 402a, 402b, 402c, 402d Coaxial terminal 403 Booster 404a, 404b Receiver (television: TV)
4021 Bracket 4022 Core wire connection CL, CL1, CL2, CL3, CL4, CL5 Coaxial cable FC F type connector

Claims (6)

It is a leaked radio wave detection device that can identify the presence or absence of leaked radio waves in the receiving equipment for satellite broadcasting in the house and the position or direction of the leaked radio wave source.
A pair of receiving antennas for detecting leaked radio waves, which are arranged at predetermined antenna intervals and have equal electrical characteristics and reception sensitivity at least in the intermediate frequency signal band of satellite broadcasting.
The first received signal and the second received signal of the frequency of the leaked radio wave to be detected received by each of the pair of receiving antennas for detecting the leaked radio wave are phase-compared by an exclusive logical sum calculation, and the first received signal is obtained. And a phase comparator that generates a voltage signal corresponding to the phase difference between the second received signal and the second received signal as a phase difference detection signal.
A signal processing unit that calculates the phase difference based on the phase difference detection signal and specifies the direction of the leaked radio wave source of the leaked radio wave to be detected by using the wavelength of the leaked radio wave to be detected and the value of the antenna interval. and, with a,
The phase comparator is
The first received signal and the second received signal are input, and the phase is calculated by an exclusive logical sum operation through a log amplifier type amplifier circuit that compresses the amplitude of each of the first received signal and the second received signal. An exclusive logic sum comparison circuit that generates the compared analog voltage signals,
An integrator circuit that performs low-pass filter processing on the analog voltage signal obtained from the exclusive OR comparison circuit, and
An amplifier circuit that generates the phase difference detection signal by setting an analog voltage signal obtained from the integration circuit and subjected to low-pass filtering into a desired voltage range.
Leakage wave detecting apparatus according to claim Rukoto equipped with. The pair of receiving antennas for detecting leaked radio waves each have a receiving central axis showing directivity in the same direction, and in the plane direction with the receiving central axis as the normal line, at least in the band of the intermediate frequency signal of satellite broadcasting. The leaked radio wave detection device according to claim 1, wherein the device is configured to have reception sensitivity. Based on the phase difference detection signal, the signal processing unit refers to a voltage / phase difference conversion table held in advance for converting the voltage value into a phase difference, or corresponds to the voltage / phase difference conversion table. The leaked radio wave detection device according to claim 1 or 2, wherein the means for calculating the phase difference is provided by the calculation formula. When both the first received signal and the second received signal to be compared are equal to or less than a predetermined threshold value, the phase comparator outputs a voltage value zero indicating that there is no leaked radio wave as the phase difference detection signal. The leaked radio wave detection device according to any one of claims 1 to 3, wherein the leaked radio wave detection device is characterized. A plurality of sets of the pair of receiving antennas for detecting leaked radio waves and the phase comparator are provided as one set, and the pair of receiving antennas for detecting leaked radio waves of each set are arranged in different directions in a plurality of dimensional plane directions. Corresponding to
The signal processing unit includes the presence of the leakage wave to the plane direction of the multi-dimensional, and is characterized in that it comprises means of identifying possible simultaneously detect the position or direction of the leakage wave sources, of claims 1-4 The leaked radio wave detection device according to any one of the above. It is a leaked radio wave detection device that can identify the presence or absence of leaked radio waves in the receiving equipment for satellite broadcasting in the house and the position or direction of the leaked radio wave source.
A pair of receiving antennas for detecting leaked radio waves, which are arranged at predetermined antenna intervals and have equal electrical characteristics and reception sensitivity at least in the intermediate frequency signal band of satellite broadcasting.
The first received signal and the second received signal of the frequency of the leaked radio wave to be detected received by each of the pair of receiving antennas for detecting the leaked radio wave are phase-compared by an exclusive logical sum calculation, and the first received signal is obtained. And a phase comparator that generates a voltage signal corresponding to the phase difference between the second received signal and the second received signal as a phase difference detection signal.
A signal processing unit that calculates the phase difference based on the phase difference detection signal and specifies the direction of the leaked radio wave source of the leaked radio wave to be detected by using the wavelength of the leaked radio wave to be detected and the value of the antenna interval. And with
Prior to the detection of the leaked radio wave, the predetermined transmission control signal of each channel in the band of the intermediate frequency signal of the satellite broadcast received through the pair of receiving antennas for detecting the leaked radio wave is demodulated to obtain the leaked radio wave of each channel. the reception quality is measured, the signal processing leakage wave detecting device you further comprising a channel selection evaluation unit for automatically setting the wavelength of the highest reception quality channel on the wavelength of the detection target of the leakage wave to section ..

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