JP2876571B2 - Microwave power supply circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-noise microwave power supply circuit for satellite communication and terrestrial communication for sharing transmission and reception.

[0002]

2. Description of the Related Art As a conventional example of this type of microwave power supply circuit, for example, a "thin power supply circuit for an in-vehicle flat phased array antenna" published in the Proceedings of the Institute of Electronics, Information and Communication Engineers, Spring 1989, C-791. There is a configuration example of a microwave power supply circuit configured by the illustrated strip line. FIG. 7 is an explanatory diagram of an antenna device incorporating a conventional microwave power supply circuit, where 1 is a transmitter, 2 is a duplexer, 3
Is a conventional microwave power supply circuit including a phase shifter, 4 is an antenna element, and 5 is a receiver.

FIGS. 8A and 8B show a structure in which a part of a conventional microwave power supply circuit incorporated in the antenna element shown in FIG. 7 is taken out, wherein FIG. 8A is a perspective view, and FIG. It is. In the figure, 6 is a strip conductor, 7 is a ground conductor plate, 8 is a dielectric substrate, 9 is a chip capacitor, and 10 is a conductive adhesive. The strip conductor 6 and the ground conductor plate 7 are provided on opposing surfaces of the dielectric substrate 8 to constitute a microstrip line. A gap is provided in the strip conductor 6, and a chip capacitor 9 is connected with a conductive adhesive 10. The same applies to the case where soldering is used instead of connection using the conductive adhesive 10.

Next, the operation will be described. In the antenna element shown in FIG. 7, the microwave generated from the transmitter 1 is input to the microwave feed circuit 3 via the splitter 2 and is radiated from the antenna element 4 into space. On the other hand, the incident wave to the antenna element 4 is input to the microwave feeding circuit 3, and is sent to the receiver 4 via the duplexer 2. here,
The microwave power supply circuit 3 is provided with a number of phase shifters for controlling the phase shift of radio waves radiated from the antenna element 4 into space and directing the beam in a desired direction. Since it is necessary to separate control signals for each phase shifter, a chip capacitor is attached to the microwave power supply circuit 3 in series with the transmission line.

FIG. 8 shows a portion of the microwave power supply circuit shown in FIG. 7 to which a chip capacitor is attached. A gap is provided in the strip conductor 6, and the chip capacitor 9 is attached with a conductive adhesive 10. It is possible to transmit only waves and cut off DC current such as a control signal of a phase shifter of a microwave power supply circuit incorporated in the antenna device shown in FIG.

[0006]

The conventional microwave power supply circuit has been configured as described above. In the antenna device shown in FIG. 7, when a high-power microwave is input from the transmitter 1, a large current flows through the chip capacitor 9 of the microwave power supply circuit shown in FIG. For example, when the characteristic impedance of the microstrip line composed of the strip conductor 6, the ground conductor plate 7, and the dielectric substrate 8 is 50Ω, when a microwave of 10 W is input, about 0.6 A of about 0.6 A is input to the chip capacitor 9. Electric current flows. Then, the chip capacitor 9 is mechanically vibrated by the microwave current, and a low-frequency radio wave determined by the material and structure of the chip capacitor 9 is generated by the piezoelectric effect. This radio wave can be detected by providing a small loop antenna on the chip capacitor 9 and measuring the power excited by the small loop antenna. One example is shown in FIG. FIG. 9 shows a result of measurement of a radio wave generated from a chip capacitor 9 to which a microwave has been input, using a spectrum analyzer connected to a minute loop antenna. The unnecessary radio wave generated from the chip capacitor 9 is a relatively low frequency of 5 to 6 MHz, but in the antenna device shown in FIG. 7, a nonlinear element such as a semiconductor constituting a phase shifter provided in the microwave feed circuit 3 is used. And appears as noise in the microwave frequency band. A part of this noise is reflected by the microwave power supply circuit 3 and the antenna element 4, sent to the receiver 5 via the duplexer 2, and appears in the reception frequency band.

The present invention has been made to solve the above problems, and has as its object to obtain a low-noise microwave power supply circuit by reducing radio waves generated by the piezoelectric effect of a chip capacitor.

[0008]

According to a first aspect of the present invention, there is provided a microwave power supply circuit, comprising: a substrate on which a strip conductor serving as an input path from a transmitter is formed; and a piezoelectric ceramic connected to the input path of the substrate. In a microwave feeder circuit having a chip capacitor composed of a non-linear element and transmitting and receiving signals, the input path from the transmitter is reduced.
At least the part where the above chip capacitor is connected
And chip capacitors in each path
Connect the above multiple chip capacitors with non-conductive resin
The current of the input path is connected to the multiple paths
It branches and flows to the plurality of chip capacitors in a distributed manner .

[0009]

[0010]

[0011]

According to the first aspect of the present invention, the input path from the transmitter is
Chip chip made of ceramic having at least piezoelectricity
The part to which the capacitor is connected is branched into multiple paths,
Connect chip capacitors to each path, and
The top capacitor is integrally fixed with a non-conductive resin and
The current in the force path is branched into the plurality of paths and the plurality of
Flow from the transmitter,
The current flowing to each chip capacitor due to the microwave input
Current due to the electric strain of the chip capacitor.
Motion and reduce the amount of chipping caused by microwave input from the transmitter.
Low frequency radio waves generated by the piezoelectric effect of
Suppress and use a microwave power supply circuit that shares transmission and reception.
And the frequency of the microwaves
To reduce noise that appears in the reception frequency band
You.

[0012]

[0013]

[0014]

[Embodiment 1] FIG. 1 is a perspective view showing an embodiment of the present invention, and is a configuration diagram showing a portion where a chip capacitor is connected to a strip conductor of a microwave power supply circuit. In the figure, 11 is an epoxy-based adhesive, and 6 to 10 are the same as those in the conventional microwave power supply circuit shown in FIG. Here, the strip conductor 6 and the ground conductor plate 7
Are provided on opposing surfaces of the dielectric substrate 8 to constitute a microstrip line. Strip conductor 6
A chip capacitor 9 is connected with a conductive adhesive 10 as in the conventional example, and the chip capacitor 9 is covered on the dielectric substrate 8 with an epoxy adhesive 11 which is a non-conductive resin. Fixed.

In the microwave power supply circuit in which the chip capacitor 9 is connected to the strip conductor 6 as described above, since the chip capacitor 9 is provided in series with the strip conductor 6, the radio wave propagated along the strip conductor 6 Of these, only microwaves are transmitted, and direct current such as control signals and low frequency radio waves are cut off. Here, when a microwave is input to the microwave power supply circuit, the ceramic chip capacitor 9 is deformed and mechanically vibrated due to the electric distortion effect of the ceramic, but the rigidity is increased by the epoxy adhesive 11 and the surroundings are increased. , The vibration damping effect is generated, and the amplitude of the vibration is reduced. Therefore, the power of low-frequency radio waves generated by the piezoelectric effect of ceramic is also reduced. Thus, when a nonlinear element such as a semiconductor is connected, the level of noise that is intermodulated by the nonlinear element and appears in the microwave frequency band can be reduced.

Next, the effect of the above embodiment will be verified by experiments. FIG. 2 is a configuration diagram of a measurement system in an experiment, and FIGS. 3 and 4 are diagrams illustrating measurement results. In the measurement system of FIG. 2, a diode is provided as a nonlinear element in the microwave power supply circuit, a microwave input from an input terminal is applied to the chip capacitor, and the chip capacitor is covered with an epoxy adhesive before and after being fixed to the dielectric substrate. The noise appearing in the reception frequency band due to the cross modulation by the diode was measured with a spectrum analyzer. 3 and 4 differ in the type of epoxy adhesive used and the nonlinearity of the diode. 3 and 4, (a) shows the measurement results before fixing,
(B) shows the measurement result after fixing. In each of the measurement results of FIGS. 3 and 4, the noise level is 1 after the fixation.
It can be seen that the noise level is reduced by about 0 dB, and that the chip capacitor is fixed to the dielectric substrate by covering it with an epoxy adhesive.

Although the above embodiment has been described with reference to an epoxy-based adhesive, it goes without saying that an adhesive of another component is also effective as long as it is a non-conductive resin that covers the chip capacitor and is fixed to the substrate.

Embodiment 2 FIG. FIG. 5 is a sectional view showing another embodiment of the present invention, and is a configuration diagram showing a portion where a chip capacitor is connected to a strip conductor of a microwave power supply circuit. In the figure, 12 is a dielectric block, 13 is an epoxy-based adhesive which is a non-conductive resin for mounting the dielectric block 12 on the chip capacitor 9, and 6 to 10 are those in the conventional microwave power supply circuit shown in FIG. Is the same as

The strip conductor 6 and the ground conductor plate 7 are provided on opposing surfaces of the dielectric substrate 8 to form a microstrip line. Also, the strip conductor 6
Is provided with a gap, and a chip capacitor 9 is attached with a conductive adhesive 10, and a dielectric block 12 is attached to the chip capacitor 9 with an epoxy-based adhesive 13. Thus, the chip capacitor 9
Are sandwiched between the dielectric block 12 and the dielectric substrate 8.

In the above embodiment, when a microwave is input, the ceramic chip capacitor 9 vibrates mechanically in the same manner as in the first embodiment, but a dielectric block 12 is mounted on the chip capacitor 9, Block 12
And the dielectric substrate 8, the amplitude of the mechanical vibration is reduced. Therefore, the power of low-frequency radio waves generated by the piezoelectric effect of ceramic is also reduced. Thus, when a nonlinear element such as a semiconductor is connected, the level of noise that is intermodulated by the nonlinear element and appears in the microwave frequency band can be reduced.

In the above embodiment, an example is shown in which a dielectric block is mounted on a chip capacitor. However, a dielectric of another shape may be used as long as the substance has a predetermined weight. It is needless to say that it is effective to attach such as.

Embodiment 3 FIG. FIG. 6 is a perspective view showing still another embodiment of the present invention, and is a configuration diagram showing a portion where a chip capacitor is connected to a strip conductor of a microwave power supply circuit. In the figure, reference numerals 6 to 11 are the same as those in the first embodiment shown in FIG. In this embodiment, the strip conductor 6 and the ground conductor plate 7 are provided on opposing surfaces of the dielectric substrate 8 to constitute a microstrip line. Further, a gap is provided in the strip conductor 6 where the chip capacitor is connected, and the strip conductor 6 is branched into three paths, each of which has a chip capacitor 9a, 9b, 9
c are connected in parallel with a conductive adhesive 10, and the chip capacitors 9a, 9b, 9c are integrally fixed with an epoxy adhesive 11 which is a non-conductive resin.

In the above embodiment, when microwaves are input, the ceramic chip capacitors 9a to 9c vibrate mechanically as in the first embodiment, but the current is distributed to the plurality of chip capacitors 9a to 9c. Therefore, the current per one of the chip capacitors 9a to 9c decreases, and the amplitude of the vibration decreases. Since the chip capacitors 9a, 9b, and 9c are integrally fixed with the epoxy adhesive 11, the rigidity is increased by the epoxy adhesive 11, and the chip capacitors 9a, 9b, and 9c are pressed from the surroundings. Becomes smaller. Therefore, it is possible to reduce the power of low-frequency radio waves generated by the piezoelectric effect of ceramic. Thus, when a nonlinear element such as a semiconductor is connected, the level of noise that is intermodulated by the nonlinear element and appears in the microwave frequency band can be reduced.

Although the first to third embodiments have described the case where the strip conductor 6 constitutes a microstrip line together with the ground conductor plate 7, other types such as a triplate strip line and a suspended line are used. It goes without saying that it is also effective on railway tracks. Although the case where the chip capacitor 9 is connected to the strip conductor 6 with the conductive adhesive 10 is shown, it goes without saying that it is effective to connect the chip capacitor 9 by soldering. Further, it goes without saying that the present invention can be applied to chip resistors as in the case of chip capacitors.

[0025]

According to the first aspect of the present invention, the transmission from the transmitter is performed.
The input path consists of at least a piezoelectric ceramic.
The part where the chip capacitor is connected is divided into multiple paths.
Branch, connect a chip capacitor to each path,
Multiple chip capacitors are fixed together with non-conductive resin
Divides the current of the input path into the plurality of paths and
Since it is distributed to multiple chip capacitors and sent,
Individual chip capacitors by microwave input from machine
Current flowing through the chip capacitor
To reduce the vibration caused by the body, the piezoelectric from the chip capacitor
In a microwave power supply circuit that shares transmission and reception by suppressing generation of low-frequency radio waves due to the effect, there is an effect that noise in a microwave frequency band due to cross modulation by a non-linear element can be reduced in a reception frequency band.

[0026]

[0027]

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a measurement system of an experiment for demonstrating the effect of the first embodiment of the present invention.

FIG. 3 is a diagram showing measurement results for demonstrating the effect of the first embodiment of the present invention.

FIG. 4 is a diagram showing measurement results for demonstrating the effect of the first embodiment of the present invention.

FIG. 5 is a sectional view showing a second embodiment of the present invention.

FIG. 6 is a perspective view showing Embodiment 3 of the present invention.

FIG. 7 is an explanatory diagram showing an antenna element incorporating a conventional microwave power supply circuit.

FIG. 8 is a configuration diagram showing a conventional microwave power supply circuit.

FIG. 9 is a diagram showing measurement results of unnecessary radio waves generated from a chip capacitor of a conventional microwave power supply circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmitter 2 Divider 3 Microwave feeding circuit 4 Antenna element 5 Receiver 6 Strip conductor 7 Ground conductor plate 8 Dielectric substrate 9 Chip capacitor 10 Conductive adhesive 11 Epoxy adhesive 12 Dielectric block 13 Epoxy adhesive Agent

──────────────────────────────────────────────────の Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H01P 1/00 H01P 3/08 H01G 1/00-1/017 H01G 4/00-4/10 H01G 4 / 14-4/42 341 H01G 13/00-13/06

Claims (1)

(57) [Claims] 1. A strip as an input path from a transmitter
Connected to the board on which the conductor is formed and the input path of the board
Chip condensates made of ceramics with improved piezoelectric properties
And a non-linear element that shares transmission and reception.
In the microwave power supply circuit, the input path from the transmitter
Duplicate at least the part to which the chip capacitor is connected.
Branches into several paths, and each path has a chip capacitor
Connect the multiple chip capacitors to a non-conductive resin
And fix the current of the input path to the plurality of paths.
And distributed to the above chip capacitors.
A microwave power supply circuit characterized by: