JPH0529813A - Interdigitate coupling circuit - Google Patents

Abstract

(57) [Abstract] [Purpose] For example, it is an object of the present invention to provide an interdigitated coupling circuit used in a microwave circuit with higher performance and wider bandwidth. An interdigitator having first and second ports 22 and 24 having a mutual spacing of λg / 4 and coupling lines 32 and 34 connected to the first and second ports and coupled to each other. In the Tate coupling circuit, the sizes and shapes of the first and second ports are the same as each other, and the number of coupling lines directly connected to the first and second ports is the same, and When the above-mentioned directly and connected coupled lines are each a combined line of a plurality of coupled lines, the number of combined lines is the same.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interdigitated coupling circuit used in a microwave circuit, for example.

In recent years, with the development of communication equipment, there has been an increasing demand for wider bandwidth and higher performance of high frequency circuits. Therefore, for example, in the coupling circuit for the microwave circuit, an interdigitated coupling circuit in which the coupling degree is increased by increasing the number of edge coupling sections is used. It is hoped that this will be realized.

[0003]

2. Description of the Related Art FIG. 4 is a structural diagram of a conventional example. Hereinafter, the operation of the drawing will be described assuming that the same loads 15 and 16 are connected to the coupling port 12 and the through port 13, respectively.

In the figure, a coupled line (hereinafter abbreviated as line) 112 and a line 111 are applied via an input port 11,
For example, the microwave appears in the through port 13 via the line 112, the line 111, the gold line 152, the line 112, the line 112, the gold line 153, and the line 131, respectively.

Microwaves propagating through the lines 112 and 131 appear at the coupling port 12 via the line 121 coupled to these lines. At this time, the microwave power applied to the input port 11 is divided in half and applied to the corresponding loads 15 and 16.

The microwave reflected by the load 15 is a gold wire.
The microwaves reflected by the load 16 via 151, 154, and the line 141 appear at the isolation port 14 via the line 141 coupled to the line 112, respectively.

[0007]

Here, as shown in the figure, the coupling port 12 and the through port 13 are different in size and shape. For example, the former height A ₁ <the latter height
B ₁ and the number of lines connected to the former is 1, whereas the number of lines connected to the latter is 2.

Therefore, the same load is applied to the coupling port.
Coupling port even when connected to 12 and through port 13
The impedance viewed from the connection point A between the line 12 and the line 121 and the load side viewed from the connection point B between the through port 13 and the line 112 are not the same.

Therefore, microwaves having different reflection phases are input to the isolation port 14 from the two ports.
Some microwaves are applied to the input port 11 from the isolation port. This hinders widening the bandwidth of the interdigitate coupling circuit.

That is, even if the same load is connected to each port, the balance of the port impedance cannot be obtained in a wide band, so that there is a problem that the high performance and wide band characteristics of the interdigitated coupling circuit are deteriorated. ..

An object of the present invention is to improve the performance and bandwidth of the interdigitated coupling circuit.

[0012]

FIG. 1 is a structural diagram of the principle of the present invention. In the figure, 22 and 24 are first and second ports having a mutual spacing of λg / 4, and 32 and 34 are coupled lines connected to the first and second ports and coupled to each other.

The dimensions and shapes of the first and second ports are the same as each other, and the numbers of coupling lines directly connected to the first and second ports are the same, and When the above-mentioned directly and connected coupled lines are each a combined line of a plurality of coupled lines, the number of combined lines is the same.

[0014]

According to the present invention, the dimensions and shapes of the first and second ports are the same as each other, and the number of coupled lines directly connected to the first and second ports are the same. In addition, when the above-mentioned directly and connected coupled lines are each a combined line of a plurality of coupled lines, the number of combined lines is the same. As a result, the first port and the second port have the same structure.

Therefore, if the same load is connected to the first and second ports, the reflected microwaves of the same phase are input to the isolation port, so that there is no microwave transmitted from this port to other ports. , It is possible to achieve higher performance and wider bandwidth of the interdigitated coupling circuit.

[0016]

FIG. 2 is a structural diagram of an embodiment of the present invention, and FIG. 3 is an example of a mounting diagram of a phase shift circuit to which the present invention is applied.

In the figure, 21 and 41 are input ports, 22 and 42 are coupling ports, 23 and 43 are isolation ports, and 2 are
4,44 are through ports, 351-354 are gold wires, and 3 is a coupling line section.

Incidentally, these coupled lines are formed on a dielectric substrate (not shown). Further, the boundary line between the coupled lines 321 and 322 and the coupled lines 33 and 323 is point D. Further, the distance between the input port 21, the isolation port 23, the coupling port 22 and the through port 24 is λg / 4 (λ
g is the wavelength on the substrate). 2 and 3 will be described below.

First, as shown in FIG. 2, the coupling port 22 and the through port 24 have the same shape and size, and a coupling line 32 (hereinafter abbreviated as a line) and a line 34 are provided at these ports, respectively. One line is directly connected.

The line 32 is a combination of two lines 321, 322, and the line 34 is a combination of the two lines 341, 342. Is becoming As a result, the structures of the coupling port 22 and the through port 24 can be regarded as the same.

Looking at the input port 21 and the isolation port 23, the shapes and dimensions of the two ports are the same, and a line 33 and a line 31 and one line each are directly connected to these ports. ing. In addition, track 33,
Neither 31 is a composite of different lines. Therefore, the input port 21 and the isolation port 23 can be regarded as having the same structure.

Now, the line 31 and the gold wire are connected through the input port 21.
Microwaves applied to 351 are line 31, gold wire 352, line
341, through the gold wire 351, the line 311, the gold wire 353, and the wire 342, and appear at the through port 24, respectively.

Further, since the lines 321 and 322 are coupled to the lines 31 and 311, a part of the microwave passing through the lines 31 and 311 appears at the coupling port 22 through the lines 321 and 322, but the through port and the cup The microwave power appearing at the ring port is half the power applied to the input port 21.

Next, the microwave is coupled to the coupling port 22.
And reflected through the same load (not shown) connected to the through port 24, respectively. 3
Via rails 33, 323 and gold wire 354 which are connected to 41, 342,
Although they appear at the isolation ports 23, the reflected microwaves do not return to the input port because they have the same structure as described above. Thereby, a wide band characteristic can be obtained.

Next, in FIG. 3, the input microwaves are applied to the coupling line section 3 via the DC block capacitor 56 and the input port 41. The coupling line section 3 has the structure shown in FIG. Therefore, microwaves of the same power appear at the coupling port 42 and the through port 44. Then, these microwaves are applied to the diodes 52 and 53 through the phase adjustment patterns 45 and 46.

On the other hand, the diodes 52 and 53 include capacitors
A bias voltage is applied through a bias supply portion 51 composed of 512 and a high frequency choke coil 511. With this bias voltage, the diodes 52 and 53 are short-circuited when they are on, and open when they are off. The phase of the reflected wave differs by 180 degrees between the short-circuited state and the open state.

Therefore, the microwaves applied to the diode are reflected here, are combined by the isolation port 43 via the phase adjustment pattern and the coupling line portion 3, and are output via the DC blocking capacitor 57.

At this time, the length and width of the phase adjustment pattern are adjusted so that the phase difference between the input microwave and the output microwave is, for example, 180 degrees correctly. In other words, the microwave input to the input port has completely the same structure of the coupling port and the through port, so if the loads connected to the respective ports have the same impedance, the broadband characteristics will be can get.

[0029]

As described in detail above, according to the present invention, the interdigitated coupling circuit can achieve higher performance and wider bandwidth.

[Brief description of drawings]

FIG. 1 is a structural diagram of the principle of the present invention.

FIG. 2 is a structural diagram of an embodiment of the present invention.

FIG. 3 is an example of a mounting diagram of a phase shift circuit to which the present invention is applied.

FIG. 4 is a structural diagram of a conventional example.

[Explanation of symbols]

 22 1st port 24 2nd port 32, 34 Coupled line

Claims (1)

Claim: What is claimed is: 1. A first and a second port (22, 24) having a mutual spacing of λg / 4 (λg is a wavelength) and being connected to the first and second ports. In the interdigitated coupling circuit having coupling lines (32, 34) coupled to each other, the dimensions and shapes of the first and second ports are mutually the same, and the first and second ports are the same. The number of coupled lines directly connected to each other is the same as each other, and when the above directly and connected coupled lines are lines that are composed of a plurality of coupled lines, the number of combined lines is the same. An interdigitated coupling circuit with a unique structure.