JPS5952844B2 - power distribution circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a power distribution circuit or a power combining circuit (herein, both are collectively referred to as a power distribution circuit) used in a power feeding circuit of an array antenna or the like.

) regarding.

In June 1978, the inventor proposed a new general theory of an antenna that can synthesize low sidelobe directivity over a wide frequency range by forming a zero point of directivity in a fixed direction over a wide frequency range. This was published as ``Wideband, low siderope array antenna directivity synthesis method'' in the Technical Research Report of the Institute of Electronics and Communication Engineers.

In this document, the conditions for keeping the direction of the zero point of n-1 directivity constant over a wide frequency range are generally (9
) has been stated that the following equation holds true.

However, i=1. 2. ..., n-1, and the connections of the common terminal pairs of the first distributors D1 to Dn to the antenna elements #1 to #n are alternately reversed.

In addition, each symbol in the above equation represents the configuration of the binomial coefficient branch feeding array antenna shown in FIGS. 1, 2, and 3, the coordinate system of the n-element array antenna in this configuration, and the feeding to the i-th element. The detailed diagram of the circuit network section shows the following:

First, pi is the branch terminal logarithm of the i-th first distributor Di, and can be expressed as pi=, 11C+-1.

S'ik is the branch terminal pair of the i-th first distributor Di;
and the common terminal pair of this distributor, and the S matrix element is shown as 5
k51 indicates an S matrix element between the common terminal pair .multidot. and the branch terminal pair .times. of the second distributor Ds.

In addition, Lik is the branch terminal pair of the i-th first distributor Di.
Indicates the transmission line length (electrical length) of the phase shifter connected to.

The same applies below. Also, (R, θ is 1.φ.1), (R
, ++tt for θ 1+1 for φ)......(R9θk
In n-1, φ, the direction indicated by -1) is the direction of n-1 zero points.

Each distributor is used with high separation.

Now, in order to satisfy the above equation (1), S'1k-8
KSI is constant, however, """L 2."'? n5 ””19
2. ”'5p1
... It was stated in the above document that (2) is sufficient.

At that time, it was also stated that the relationship between the transmission line length and the zero point direction of the directivity is given by the following equation.

Lik−Lni = −d (sinθki −co
sφki +1 to 10 sinθ, +1+ to CO8φ
stnθ, -cosφkn-1)
... (3) However, i=1.2. -, n
−1, = 1°2, ..., pl Therefore, the present invention satisfies the above formula (2) when the number of element antennas constituting the array antenna is 3, and is used in the feeding circuit of the array antenna. A first object of the present invention is to provide a power distribution circuit with a simple configuration that allows a wideband antenna to be obtained.

The second object is to provide a power distribution circuit that realizes a complex current, which was not described in the above-mentioned literature, by using this circuit configuration.

In the power distribution circuit of the present invention, three
Consists of one divider, two 2-way dividers that output signals of equal amplitude, and first to fourth phase shifters of a predetermined length of line, n =
In case 3, the above equation (2) holds true, and a power distribution circuit effective for the power feeding circuit of the array antenna is obtained.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 shows three power distribution circuits according to an embodiment of the present invention.
A circuit configuration when applied as a feeder circuit for an element array antenna is shown.

This power supply circuit 10 includes a three-way divider 11 that outputs in-phase and equal amplitude signals to three branch terminal pairs 11b, IIC, and 11d in response to an input to a common terminal pair 11a, and a common terminal pair 12a.
, 13a, two branch terminal pairs 12b, 1
First and second two-way dividers 12 and 13 that output in-phase and equal amplitude signals to 2C and 13b and 13C, and first to second line-shaped dividers that provide a predetermined amount of phase shift depending on the transmission line length (electrical length). 4
phase shifters 14, 15, 16, 17 and 1 divider 18.1
It consists of 9.

For example, the 3-way divider 11 is M3V- manufactured by ANZAC.
50, and the 2-way distributors 12 and 13 are MTV- manufactured by the same company.
50 can be used.

The common terminal pair 12a of the first two-way divider 12 is connected to one branch terminal pair 11d of the three-way divider 11, and the first and second common terminal pairs 12b and 12C of this two-way divider 12 are connected, respectively. Input terminal pairs 14a and 15a of phase shifters 14 and 15 are connected.

The other two branch terminal pairs 11b and 11C of the three-way divider 11 are connected to the input terminal pair 16a of the third and fourth phase shifters 16 and 17,
17a is connected.

Output terminal pair 16 of these third and fourth phase shifters 16 and 17
b, 17b are the branch terminal pair 13b of the second two-way divider 13.
, 13C are connected.

Element antenna #2 is connected to the common terminal pair 13a of the second two-way divider 13.

Note that the output terminal pair 14b of the first and second phase shifters 14 and 15
, 15b has an input terminal pair 18a of the 1-distributor 18, 19,
19a is connected, and these output terminal pair 18b, 19b
Element antenna #3° #1 is connected with a polarity opposite to that of element antenna #2.

However, the 1-distributors 18 and 19 are shown to clarify the relationship with the general theory of the above-mentioned document, and in reality there is no need for distribution, so they may be omitted.

Further, for example, a dipole antenna can be used as the element antenna connected to the output terminal pair 19b, the common terminal pair 13a, and the output terminal pair 18b, but other types of antennas may be used.

Connect as described above, common terminal pair 1 of 3-way divider 11
When a signal to be transmitted is supplied to 1a, it is output to three distributed terminal pairs 19b, 13a, and 18b, and element antenna #1. #2. #3 is supplied.

It is preferable to use the three-way divider 11 and the two-way divider 12, 13 that have a high degree of separation between the respective pairs of branch terminals.

According to the above embodiment, it will be described below that the above formula (2) is satisfied when the number of element antennas is 3.

In FIG. 4, considering that the part surrounded by the dashed-dotted line corresponds to the distributor Ds in FIG. 1, i=1, 2. In case 3, S'ik and Sks i are found and their product is found as shown in the following table.

Therefore, it is clear that the condition S'ik −Sks i =constant is satisfied.

Next, in order to satisfy equation (3), the line lengths of the first to fourth phase shifters are L3□ and L1□.

L2□, L2, (electrical length) can be selected as shown in the table below.If the line lengths of the first to fourth phase shifters are selected in this way, the zero point of directivity can be set in a fixed direction over a wide band. can be made.

However, this is not the only case in which selection is made.

For example, in the above embodiment, the first and second two distributors 12, 13
The case of outputting in-phase and equal amplitude signals was described as follows.

However, a divider that outputs signals of opposite phase and equal amplitude may be used as one or both of the two dividers.

In this case, the line lengths of the first to fourth phase shifters are selected accordingly.

Furthermore, these phase shifters are not limited to line-type phase shifters in which the amount of phase shift is determined by the line length, but other types of phase shifters may also be used.

Generally, there is a phase shift inside the distributor, but this can be treated as part of the phase shift caused by the phase shifter, and therefore does not cause any practical problems.

For example, even if the phase shifts within the divider are not necessarily equal between the common terminal pair 11a of the three-way divider 11 and the branch terminal pairs 11b and 11C511d, they are shifted by the first to fourth phase shifters 14 to 17. This is because the phase amount can be corrected.

According to the embodiment shown in FIG. 4, a three-element array antenna with a simple structure that can create zero points in two desired fixed directions over a wide frequency range can be obtained.

In addition to the above, as a modification of the present invention, the power distribution circuit of the present invention can also be used as a power feeding circuit to radiate in phase in a wide band in a fixed direction, instead of creating zero points in a wide band in two fixed directions. can.

It can also be used in a power supply circuit in which only one zero point is created and the radiation characteristics of the others are in phase.

Further, the present invention can be applied not only to a power feeding circuit for a three-element array antenna, but also to a power distribution circuit that generally divides and outputs signal power into three.

Furthermore, the present invention can be used not only for distributing power but also as a combining circuit that inputs signals from three terminal pairs.
This is clear from the principle of reciprocity in passive circuits.

According to the present invention, it is possible to obtain a power distribution circuit that can distribute a specific signal into three desired signals focusing on phase and amplitude over a wide frequency range as described above.

Furthermore, the present invention has the advantage that the entire structure is extremely simple, since all the distributors can be constructed of equal-amplitude distributors.

Generally speaking, the second divider Ds in FIG. 1 needs to have the characteristic of outputting signals with different amplitudes to each branch pair.
This is because the present invention can be configured with equal-amplitude dividers, so a hybrid two-way divider or three-way divider can be used which has a wider band and better amplitude characteristics than a directional coupler.

Furthermore, since the present invention does not use a resistive attenuator, another major feature is that there is no unnecessary power loss.

[Brief explanation of drawings]

1 to 3 are diagrams for explaining the general theory of a conventionally known n-element array antenna, and FIG. 4 is a circuit configuration diagram of an embodiment of the present invention. 10...Power supply circuit, 11...3 distributor, 12...1st 2 distributor, 13...
2nd 2-divider, 14-17... 1st-4th phase shifter, 18, 19... 1-divider.

Claims (1)

[Claims] 1. A three-way divider that outputs a signal of equal amplitude to three branch terminal pairs in response to input to a common terminal pair, and a three-way divider that outputs a signal of equal amplitude to three branch terminal pairs in response to an input to a common terminal pair, and a common terminal pair that is connected to one branch terminal pair of this three-way divider. a first two-way divider that outputs signals of equal amplitude to two branch terminal pairs in response to an input to the two-way divider, and first and second phase shifters respectively connected to the branch terminal pairs of this two-way divider. , third and fourth phase shifters respectively connected to other branch terminal pairs of the three-way divider, and two branch terminal pairs connected to these third and fourth phase shifters and their common terminal pairs. and a second two-way divider that outputs signals of equal amplitude to these two branch terminal pairs with respect to the input to the three-way divider. A power distribution circuit for distributing and outputting power to a common terminal pair of a second two-way divider and a second two-way divider.