JPH0693568B2 - Series power supply circuit - Google Patents

Description

TECHNICAL FIELD The present invention relates to a series feeding circuit used for a feeding circuit for an array antenna.

[Conventional technology]

FIG. 5 is a block diagram showing a conventional series feed circuit described on pages 222 to 224 of, for example, "Antenna Engineering Handbook" (edited by The Institute of Electronics and Communication Engineers, published by Ohmsha).
In the figure, 1-5 are couplers, 6-9 are each couplers 1-5.
, 10 is a matching terminal connected to the coupler 5 at the rear end, P ₀ is an input terminal connected to the coupler at the front end, and P _{1 to} P ₅ are each coupler 1 5 to 5, and the couplers 1 to 5 are connected in cascade via the main lines 6 to 9.

Next, the operation of this series feeding circuit will be described.

The wave incident on the input terminal P ₀ of the coupler 1 at the front end is the main line 6
The required amount of electric power is taken out to the output terminals P _{1 to} P ₅ of each of the couplers 1 to 5 while being propagated through the couplers 1 to 5 through 9 to 9, and the remaining electric power is output from the coupler 5 at the rear end. It is absorbed by the matching end 10. At this time, the phase distribution of the waves output to the output terminals P _{1 to} P ₅ is determined by the electrical lengths of the main lines 6 to 9.

Now, if it is desired to obtain electric powers of different phase distributions at equal intervals from the output terminals P _{1 to} P ₅ , the electrical lengths of the main lines 6 to 9 must be selected to be equal. I.e. the length L ₀ is equal to the line length of the main line 6-9, adjacent phase difference between the output terminals P ₁ to P ₅ and phi ₁ to [phi] ₅ power phase of the output terminals P ₁ to P ₅ Then, it is expressed by the following equation.

However, φ _{1 to} φ ₅ : Phase of the wave extracted at each end P _{1 to} P ₅ λg: Wavelength of the main lines 6 to 9 L ₀ : Line length of the main lines 6 to 9 As seen from this equation, the distance between adjacent terminals Since the phase difference changes depending on the wavelength λg, the phase difference can be used for a power feeding system of the frequency scanning antenna.

[Problems to be solved by the invention]

However, in the conventional series feed circuit, in order to obtain the phase distributions of different adjacent phases at equal intervals as described above, the main line 6 to
Since it is necessary to make the lengths of 9 equal, the reflected waves from the couplers 1 to 5 are superposed in phase at the frequency of the guide wavelength λgn satisfying the following expression, and VSWR is significantly deteriorated.

However, n: integer The VSWR characteristic at this time is shown in FIG.

As can be seen from this figure, in the conventional series feed circuit, VSWR is significantly deteriorated periodically, so that there is a problem that the usable frequency band width is limited to this frequency interval and it cannot be used in a wide band. In addition, there is a problem that the amplitude and phase of the waves extracted at the output terminals P _{1 to} P ₅ vary greatly due to the deterioration of VSWR.

The present invention has been made to solve the above problems, and prevents VSWR from significantly deteriorating over a wide band, and also allows a wave incident from the terminal P ₀ to have a plurality of output terminals with a required amplitude and phase distribution. The purpose is to obtain a series power supply circuit that can be taken out to the.

[Means for solving problems]

A series power supply circuit according to a first invention of the present application is provided with a matching termination at the end, and the length of each main line connecting each coupler is L ₀ + 2L
Based on d (Ri-0.5), set different lengths and provide each correction line between each coupler and each output terminal to correct the electrical length of each main line. The length M _K is _calculated by the following equation: (L ₁ + M ₁ ) −M ₀ = (L ₂ + M ₂ ) −M ₁ ＝ (L ₃ + M ₃ ) −M ₂・ ・ ・ ＝ (L _{K + 1} + M _{K + 1−} M _K = L ₀ (note that the main line and the correction line that are farther from the input end side as the subscripts of L and M increase) are set.

Further, the series power supply circuit according to the second invention of the present application is configured such that a correction line calculated by the above formula is provided at the terminal end instead of the matching terminal and the output terminal is connected.

[Action]

The main lines of different lengths between the couplers in the present invention disperse the phase of the reflected wave reflected from the coupler to the input terminal P ₀ , and suppress VSWR from significantly deteriorating at a specific frequency.

The correction line corrects the electrical length of the main line caused by the different lengths of the main line, and operates so as to obtain the electric power of the phase distribution having different phases at equal intervals from the output terminal of each coupler.

Example of Invention

FIG. 1 is a block diagram showing an embodiment of the present invention,
1-5 are couplers, 6-9 are main lines, 10 are matching terminations, 11-
Reference numeral 15 is a correction line, P ₀ is an input terminal of the coupler 1 located at the front end, and P _{1 to} P ₅ are output terminals connected from the respective couplers 1 to 5 via the correction lines 11 to 15.

Here, the couplers 1 to 5 are connected in cascade via the main lines 6 to 9, and the couplers 1 to 5 and the output terminals P _{1 to} P _{5 are connected.}
Correction lines 11 to 15 are connected between and.

The lengths L _{1 to} L ₄ of the main lines 6 to 9 are L ₀ ± Ld with L ₀ as an average value.
Different lengths are selected within the range.

For example, if Ri is a uniform random number in the (0,1) interval, then L _{1 to} L ₄ have a length represented by the following equation.

Li = L ₀ + 2Ld (Ri−0.5) (3) (i = 1 to 4) The length Ld is determined by considering as shown in FIG. That is, as in the conventional case, all main lines 6 to 9 have the same length, and L ₀ ± Ld
It seems that the frequency that becomes the peak of VSWR when it is changed by covers the used frequency band. Under this condition, if the wavelength of the lower limit frequency of the used band is λg, Ld is approximately given by the following equation.

Further, the lengths M _{0 to} M ₄ of the correction lines 11 to 15 are the same as those of the adjacent output terminals P ₁ to
Make sure that the line length difference from the input terminal P ₀ between P ₄ is L ₀ .
The length is determined by the following formula.

_{(L 1 + M 1) -M} 0 = (L 2 + M 2) -M 1 = (L 3 + M 3) -M 2 = (L 4 + M 4) -M 3 = L 0 (5) In this series feed circuit , The wave incident on the input terminal P ₀ is partially propagated through the main lines 6 to 9 through the couplers 1 to 5 so that part of the power is extracted from the output terminals P _{1 to} P ₅ , and the remaining power is It is absorbed by the matching end 10.

The amplitude of the power wave extracted at the output terminals P _{1 to} P ₅ can be set to a required amplitude distribution depending on how the coupling amounts of the couplers 1 to 5 are applied.

Also, the phase φ ₁ of the wave of electric power taken out at the output terminals P _{1 to} P ₅
˜φ ₅ is determined by the electrical lengths of the main lines 6-9 and the correction lines 11-15. From the condition of the fifth expression, this phase distribution is a phase distribution in which the phases are different at equal intervals, as in the conventional series feed circuit. At this time, the phase difference between the adjacent terminals of the output terminals P _{1 to} P ₅ is represented by the first expression and can be used for a frequency scanning antenna or the like.

Next, in the VSWR of this series power feeding circuit, since the main lines 6 to 9 have different lengths, all the reflections of the couplers 1 to 5 are not superimposed in phase at a specific frequency. .
Therefore, the VSWR characteristics are as shown in FIG. 4, and there is no significant deterioration in VSWR over a wide band of frequencies. Further, for this reason, fluctuations in the amplitude and phase of the waves extracted at the output terminals P _{1 to} P ₅ are reduced.

FIG. 2 is a block diagram showing another embodiment of the present invention.
In the embodiment of FIG. 1, of the waves incident from the input terminal P ₀ , the power of the waves remaining without being extracted at the output terminals P _{1 to} P ₅ connected to the couplers 1 to ₅ is discarded to the matching termination 10. However, in the embodiment of FIG. 2, this electric power is taken out to the output terminal P ₆ and is effectively used.

Operation is similar to the series feed circuit of FIG. 1, the output terminal P ₁
The amplitudes of the waves extracted to P ₆ can be made to have a required amplitude distribution depending on how to select the coupling amount of the couplers 1 to 5.

Further, by adding the condition of the following formula in addition to the condition of the fifth formula, the phase distribution of the wave extracted from the output terminal becomes a phase distribution having different phases at equal intervals.

L ₅ −M ₄ = L ₀ (6) In addition, the VSWR characteristics show that the couplers 1 to 5 have different main line 6 lengths.
Cascaded through ~ 9, there is no significant VSWR degradation over a wide band of frequencies.

Although the number of couplers is five in the above embodiment, the number of couplers is not limited to five and may be more than one. The larger the number of couplers, the more remarkable the effect of the present invention.

〔The invention's effect〕

As described above, according to the present invention, the lengths of the main lines connecting the couplers are different from each other, and the correction line for correcting the electrical length of the main line is provided between the coupler and the output terminal. Since it is configured, VSWR is not significantly deteriorated over a wide band of frequencies, and the output wave amplitude and phase fluctuations are small. Further, in the second invention, the correction line is also provided at the terminal end, so that the electric power can be effectively used.

[Brief description of drawings]

FIG. 1 is a block diagram showing a series power feeding circuit according to an embodiment of the present invention, FIG. 2 is a block diagram of a series power feeding circuit according to another embodiment of the present invention, and FIG. 4 is a characteristic diagram showing VSWR characteristics of the present invention, FIG. 5 is a block diagram showing a conventional series feeding circuit, and FIG. 6 is a characteristic diagram showing VSWR characteristics of a conventional series feeding circuit. Is. In the figure, 1 to 5 are couplers, 6 to 9 are main lines, 10 is a matching termination, 11 to 16 are correction lines, P ₀ is an input terminal, and P _{1 to} P ₆ are output terminals. In the drawings, the same reference numerals indicate the same or corresponding parts.

Front page continuation (72) Inventor Moriyasu Miyazaki 5-1-1, Ofuna, Kamakura-shi, Kanagawa Mitsubishi Electric Corporation Information Electronics Laboratory (72) Inventor Norio Takeuchi 8-1-1 Tsukaguchihonmachi, Amagasaki City, Hyogo Prefecture Ryoden Co., Ltd., Communication Equipment Factory (56) Reference JP-A-51-57150 (JP, A)

Claims (2)

[Claims] 1. A plurality of couplers are connected in cascade through a main line and a matching termination is provided at the end, and an incident wave to the input end of the coupler at the beginning is supplied to each coupler through the main line. , While sequentially extracting the electromagnetic waves of the required power from the output terminals connected to each of the above-mentioned couplers and supplying them to a power feeding system such as an antenna,
In the series feed circuit configured to absorb the remaining power in the matching termination, the length of each main line connecting the above-mentioned couplers is set to L ₀ + 2Ld (Ri-
0.5) (where L ₀ is the average length of the main line, Ld ≈ 1/4 · λg, λ
g is the wavelength of the frequency used, and Ri is a uniform random number in the (0,1) interval. ), Set different lengths, and provide a correction line between each coupler and each output terminal to correct the electrical length of each main line. _K is _calculated by the following equation: (L ₁ + M ₁ ) −M ₀ = (L ₂ + M ₂ ) −M ₁ ═ (L ₃ + M ₃ ) −M ₂・ ・ ・ ・ = (L _{K + 1} + M _{K + 1} −M A series feed circuit characterized by being set according to _K = L ₀ (note that the main line and the correction line are located farther from the input end side as the subscripts of L and M increase). 2. A plurality of couplers are connected in cascade via a main line, and an incident wave to the input end of the coupler at the starting end is supplied to each coupler via the main line, and electromagnetic waves of necessary power are sequentially supplied. In a series feeding circuit that takes out from the output terminal connected to each coupler and supplies it to a feeding system such as an antenna, the length of each main line connecting each coupler is L ₀ + 2Ld (Ri−
0.5) (where L ₀ is the average length of the main line, Ld ≈ 1/4 · λg, λ
g is the wavelength of the frequency used, and Ri is a uniform random number in the (0,1) interval. ), Set different lengths, and provide each correction line for correcting the electrical length of each main line between each coupler and each output terminal, and set the length of each correction line. M _K is _calculated by the following equation: (L ₁ + M ₁ ) −M ₀ = (L ₂ + M ₂ ) −M ₁ = (L ₃ + M ₃ ) −M ₂・ ・ ・ ・ = (L _{K + 1} + M _{K + 1} ) -M _K = L ₀ (Note that the main line and the correction line that are farther from the input terminal side are shown as the subscripts of L and M increase.) A series feeding circuit, characterized in that a calculated correction line is provided and the output ends are connected.