JPS60223303A - Microwave switch matrix - Google Patents

Abstract

PURPOSE:To miniaturize the entire device by providing a line length adjusting section in a module so as to optimize the length of line thereby reducing the amount of reflection produced on input/output lines and eliminating the need for circuit components such as an isolator for absorbing a reflected wave. CONSTITUTION:A unit module 1 of a switch matrix is constituted in a form of a microwave integrated circuit, a directional coupler 4 of 1/4-wavelength is arranged on the way of a microstrip line 3 for input on a ceramic substrate 2 and a branched input signal is fed to an amplifier whose gain is variable. A resistive termination 6 is arranged at other end of a branch line so as to absorb the reflected wave. A signal switched on/off substantially by changing over the gain of the amplifier 5 is led to a resistive termination 9 from a directional coupler 8 comprising a microwave IC arranged at the back side from a through-hole 7 and a branched output is transmitted to an output line 10. The line length adjusting section 11 in which the input line 3 is meandered and a line length point contact section 12 of the output line 10 select a phase angle in the unit module as 0.5pi so as to reduce the input/output standing wave ratio as a whole for the combinations of many unit modules.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a microwave switch matrix, more specifically, a directional coupler that connects microwave signals from a plurality of input terminals to a plurality of output terminals in any combination. and a microwave switch matrix outputting via a switch amplifier.

[Background of the invention]

Fig. 1 shows a functional diagram of the basic connections of the switch matrix. In order to fully connect the plurality of input signal terminals 1' to 1' // and the plurality of output signal terminals 2' to 2'', Crosspoint switch 1'-1 at each intersection of vertical and horizontal tracks
', 2/-2' are provided to enable connection between arbitrary inputs and outputs.

In conventional microwave switch matrices, reflections occur when switches are attached directly to the lines, so the actual configuration uses directional couplers to transfer signals between input and output lines to minimize line reflections. Then, the amplification gain of the amplifier inserted in the middle was changed to perform 0N10FI. Microwave switch matrices are generally
It is constructed by modularizing and arranging a large number of loss point switches as described above. Therefore, in the conventional device, when the number of input signals and the number of output signals increases, residual reflections from each module accumulate, resulting in a problem that the output standing wave ratio of the device deteriorates.

[Purpose of the invention]

An object of the present invention is to provide a microwave switch matrix having a structure in which the standing wave ratio of input/output lines is good even when the scale is increased.

[Summary of the invention]

In order to achieve the above object, the present invention has a microwave switch matrix in which unit modules are arranged periodically.
The line length is optimized to prevent the superposition of unique reflections common to each module.

[Embodiments of the invention]

Hereinafter, the present invention will be explained by implementing the invention. The unit module 1 of the microwave switch matrix (MSM) is
It is constructed in the form of a microwave integrated circuit (IC),
A quarter wavelength directional coupler 4 is arranged in the middle of the input microstrip line 3 on the ceramic substrate 2,
The branched input signal is applied to a variable gain amplifier 5. The non-reflection termination 6 is disposed at the other end of the branch line and serves to absorb reflected waves. By switching the gain of the amplifier 5, the signal, which is substantially opened and closed, is guided from the through hole 7 to the directional coupler 8, which is configured with a microwave IC placed on the back side, to the non-reflection termination 9, and is branched. The generated output is transmitted to the output line 10.

Meandering line length adjustment section 11 of input line 3 and output line 1
The line length adjusting section 12 of 0 sets the phase angle within the unit module to 0.5π to reduce the output standing wave ratio of the entire MUM, which is a combination of many unit modules.

Next, according to the present invention, the line length adjustment section 11 is installed in the unit module.
．． 12 functions will be explained.

Now, when n modules are arranged at equal intervals, the complex reflection coefficient at the input or output end is given by the following formula: 2π β = □ λ.

Here, Fo: Specific reflection coefficient of the module α: Attenuation constant of 1 module λg: Effective wavelength of 1 fM path t: Line length attenuation constant α of 1 module It is determined by the loss and the loss due to the length of the line.

FIG. The effect of optimizing the length adjustment section is shown. The horizontal axis represents the isolateral line length within a unit module or the module spacing phase angle, and the increase rate of reflection coefficient JF//'of
is shown on the vertical axis.

When the line length within the module is expressed as a phase angle and βL=π (radians), the reflection coefficient is 3.
It can be seen that the power increases by a factor of 64, or more than one order of magnitude, and the standing wave ratio of the person and the output line deteriorates.

The magnitude of the reflection coefficient is 0.0 for a unit module.
It can be suppressed to about 5 times.

〔Effect of the invention〕

According to the present invention, by providing a line length adjustment section within the module, the amount of reflection that occurs on the output line can be reduced, so circuit components such as isolators for reflection absorption, which were necessary in conventional methods, are omitted. However, it has the effect of simplifying the equipment.

Further, according to the present invention, the phase angle can be optimized even if the external dimensions of the module are freely designed, which has the effect of downsizing the entire device.

[Brief explanation of drawings]

FIG. 1 is a connection function diagram of a switch matrix, FIG. 2 is a plan view showing the structure of an embodiment of a switch matrix according to the present invention, and FIG. 3 is a diagram showing the reflection coefficient increase rate in an embodiment of the present invention. Measurement result? FIG. 1'~1""...Input signal terminal, 2'~2""...
Output signal terminal, 1/s/, 1/2/... cross point switch, 3'+4'... non-reflection termination, 1.
...Unit module, 2...Ceramic substrate, 3...
・Microstrip line, 4... Directional coupler, 5
...Amplifier, 8...Directional coupler, 10...Output line, 11.12...Line length adjustment section. Honor 1 Evil 2. 2.. 2.” 2”” 4fLis'f3

Claims (1)

[Claims] 1. A plurality of output signal lines intersect with a plurality of input signal lines, and a coupler and a switch amplifier are arranged at each of these intersections, so that input and output signals can be connected in any combination. A microwave switch matrix characterized in that, in the microwave switch matrix as described above, reflected waves crossing each input and output line are completely canceled out. 2. The microwave switch matrix according to claim 1, characterized in that the input signal line and the output signal line are provided with meandering portions so as to be miniaturized with a desired line length.