JPS58141003A - Waveguide switch - Google Patents

Abstract

PURPOSE:To obtain large isolation through miniaturized constitution by providing a lateral and a longitudinal slot at a path through which a microwave signal leaks. CONSTITUTION:For the longitudinal slot 16, plural lateral slots 18 are provided crossing at right angles. A signal leaking from the connection part of a stator 11 and a rotor 13 propagates the gap between the stator and rotor to leak to another waveguide, but is cut off by the low-pass filter consisting of the slots provided there and the gap to be attenuated greatly in the circumferential direction of the rotor and in the direction parallel to the axis. In a figure, l5, l6, and l7 are <=1/8 wavelength and much less than those of a conventional quarter- wavelength choke type, so that the diameter of the rotor is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a waveguide switching device that operates at frequencies above the microwave band.

The waveguide switching device uses a waveguide, so it has low loss.
It is also used in many fields because it can conduct large amounts of electricity. For example, it is used when switching signal paths on the output side of a high-output amplifier or when switching signals on the input side of a low-noise amplifier.

Although the waveguide switching device has the above-mentioned feature of being able to handle high power and having low loss, it has the drawbacks of slow switching speed and large amount of power required for switching.

This is because the rotating element (hereinafter referred to as a rotor), which constitutes the core of the waveguide switching device, is heavy and large, and its inertia is large.

FIG. 1 is a sectional view of a conventional waveguide switching device showing the above example. In the figure, 1 is a stator provided with a plurality of waveguide openings 2, and other waveguide circuits are connected to the openings 2-. 3 is a rotor which is a switching element of a waveguide switching device,
It begins to rotate around the shaft 5. The rotor 3 and the stator I are configured to rotate while maintaining a small gap i.

In Fig. 1, between waveguide openings 2a and 2d, between 2b and 2C.
By rotating the rotor 3, the waveguide openings 2a and 2b and 2C and 24 are connected.

Conventionally, a small gap is provided between the rotor 3 and the stator 1 for this switching, as described above, but this gap causes unnecessary microwaves to propagate between the waveguides that are not intended to be connected. It also serves as a road. Normally, the degree of leakage of this unnecessary signal is called isolation, and this isolation requires a fairly large value, for example, about 90 dB in the case of an FM signal. Therefore, conventional waveguide switching devices are used to increase this isolation.
A so-called quarter-wavelength rotor yoke has been used in which a large number of slots 6 with dimensions as shown in FIG. 1 are provided in the rotor 3. j! s,j! A value near a quarter wavelength of the 4te frequency was selected. Therefore.

The rotor 3 shown in FIG. 1 has a disadvantage in that the diameter is considerably large and the external dimensions of the switching device are large. In addition, in order to obtain a sufficiently thick isolation, it may be necessary to further increase the number of slots 6, and the rotor may become even larger than K.

An object of the present invention is to provide a small waveguide switching device which is based on one or more ideas and has a faster switching speed and lower driving power than conventional waveguide switching devices.

A detailed explanation of the present invention will be given below.

) In order to obtain a waveguide switching device with higher speed and lower driving power, the diameter of the rotor 3 should be reduced. However, reducing the diameter of the rotor means that it will no longer be able to accommodate the aforementioned quarter-wavelength chirping, which will degrade the isolation. Therefore, in the switching device of the present invention, it is sufficient to find a structure that is small and can provide a large isolation ring. Therefore, it is first necessary to analyze what path the microwave signal takes to leak. FIG. 2 shows a sectional view taken along line XX in FIG. 1. The stator 1 and rotor 3 are close to each other across a narrow gap Y3', but this gap can be considered to be a parallel plate line with very low impedance. The waveguide section of the waveguide switch (portion 4 in FIG. 1) is a rectangular waveguide with four sides closed.1. The TExo wave propagates, but the gap between the stator and rotor becomes a parallel plate line with both ends open, so the wave propagating there is similar to the tiTEM mode. TEM
Basically, mode waves can be propagated from direct current, and the direction of propagation is not limited to the circumferential direction of the rotor.
It also propagates in a direction parallel to the rotor axis.

Conventional waveguide switching devices are therefore unable to obtain high isolation values due to the leaked signals, and the leaked waves cause resonance, which causes a dip (abnormality) in the pass characteristics of the waveguide switching device. This is considered to be due to the occurrence of a significant resonance (loss increase). Therefore, simply increasing the number of slots 6 will only unnecessarily increase the diameter of the rotor and will not solve the essential problem. Therefore, the waveguide switching device according to the present invention solves the above problems and obtains high insulation by using vertical and horizontal slots in the sweater or stator, which act as low-frequency wave devices having the characteristics shown below. h was provided on both the rotor and stator. In this case, a plurality of slots are provided in a direction parallel to the axis of the rotor and in a direction parallel to the circumference of the rotor. The slots serve as inductive elements in the low-frequency wave generator, and the portion without slots serves as a gap between the rotor and stator and serves as a capacitive element. If slots are provided vertically and horizontally like this,
Therefore, propagation of the TEM mode wave is blocked in either direction, and large isolation is obtained, and at the same time, abnormal resonance does not occur. In addition, the quarter-wavelength chiral shape required a quarter-wave length for the slot spacing, but by using a low-frequency waveform, the slot spacing was reduced to less than one-eighth wavelength. Therefore, the diameter of the rotor can be reduced. Embodiments will be described in detail below with reference to the drawings.

FIG. 3 shows an embodiment of the waveguide switching device according to the present invention, in which the slot 1g parallel to the circumferential direction described above (hereinafter referred to as lateral slot) is provided. The horizontal slot is
There are several installed. FIG. 4 is a view of the rotor of the waveguide switching device viewed from the direction marked OA in FIG. 3. A plurality of horizontal slots 1g are provided perpendicularly to the vertical slot 16. Since microwave signals leak between adjacent waveguides, the parts of the rotor 13 that become leakage paths (the upper right and lower left parts in Fig. 3) are provided with many slots in the vertical and horizontal directions. There are fewer slots in the portion between the waveguides (lower right and upper left portions in FIG. 3). The gs diagram is a perspective view of the rotor and shows how the slots are provided. 17 is a bearing that supports the rotor. In Figure 3, the horizontal thrower (18) has an arcuate cross-section for ease of machining.In particular, it must be an arc to prevent leakage from the joint between the stator 11 and rotor 13. The signal propagates through the gap between the stator and rotor and tries to leak to another waveguide, but the low-frequency P wave 1lIK, which is made up of specially provided slots and gaps, is blocked and flows in the circumferential direction of Cao-Yu. It is also greatly damped by 4 in the direction parallel to the axis. FIG. 6 shows an equivalent circuit of a low frequency wave generator consisting of a rotor and a stator. 6th tIIiK sea 19
．． The capacitive elements 20 and 21 are formed in the gap between the rotor and the stator, and the elements 22 and 23, which are composed of inductance and capacitance, are arranged in the slot. The depth of the slot is selected so that the parallel resonance frequency of the inductance and capacitance is equal to or higher than the horse wave number used by the waveguide switch. ... Figure 7 shows the attenuation versus frequency characteristics of a low-frequency wave generator consisting of a stator and a rotor. Normally, the problem with a low-frequency converter is the characteristics of the passband, but in this case, only the fast-cutting characteristics of the operating frequency foK are a problem.

J in Figure 3! I, Jls, J! The dimensions of the rotor 7 are equal to or less than one-eighth wavelength, and are significantly smaller than the conventional one-fourth wavelength rotor type, and as a result, the diameter of the rotor 13 can be reduced.

One embodiment has been described above, and the waveguide switching device according to the present invention forms a low-frequency P-wave cut-off circuit by providing vertical and horizontal slots in the portion that becomes the leakage path of the microwave signal. death.

To effectively prevent signal leakage in both vertical and horizontal directions. As a reminder, it is possible to obtain large isolation in a small size. As the rotor diameter decreases, the moment of inertia decreases approximately in proportion to the fourth power of the diameter, so reducing the IT diameter has a large effect. That is, if the driving power is the same, the switching speed will be faster9, whereas if the switching time is the same, the driving power will be smaller. To explain the effect using an actual measurement example, with a conventional waveguide switching device, the rotor diameter is 1
Case 1 In the waveguide switching device according to the present invention, the rotor diameter can be reduced to 80 mm, and as a result, the moment of inertia of the rotor is reduced to one-third. Also, when driven with the same driving power,
The time required for switching is 1 g, 5 milliseconds for the conventional method, and 95 milliseconds for the present invention.
m seconds, a reduction of more than 40 seconds. Note that the isolation level obtained is more than xtodB, which is superior to conventional switching devices.

The embodiment described above is characterized in that vertical and horizontal slots are provided in the portion that becomes the leakage transmission path of the microwave signal.
Various modifications are possible. The number of slots should be selected appropriately depending on the degree of isolation required. In addition, in the embodiment, the slots were placed in the rotor 1&ff with emphasis on ease of machining, but the slots were copied from the stator IIK.

It is also possible to provide it in the stator equipment. However, machining is difficult, so the slots are formed using casting methods, etc. It is also possible to provide the slots at positions opposite to each other in the stator and rotor. In either case, slots must be provided vertically and horizontally.

According to the present invention as described in detail above.

Compared to conventional methods, it is possible to realize a waveguide switch that has a faster switching speed, lower driving force, and is smaller.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a conventional waveguide switching device, and Figure 2 is a cross-sectional view of a conventional waveguide switching device.
A partial view of the cross section taken along line X-X in the figure, FIG. 3 is a horizontal 11fr[fi diagram showing an embodiment of the waveguide switching device according to the present invention, and FIG. 4 is a rotor of the waveguide switching device of FIG. 3. 5 is a perspective view of the rotor section of the waveguide switching device of FIG. 3, FIG. 6 is an equivalent circuit diagram of the leakage cutoff section, and FIG. 7 is a leakage cutoff characteristic diagram. 1.11... Stator 2, (2a to 2ct), 12. (128-12d)・
...Waveguide opening 3.13...Rotor 4.14...Waveguide provided in the rotor 6.16...
・Vertical slot 18...Horizontal slot 2j Figure 22 Figure 3 Figure 4

Claims (1)

[Claims] A stator having a cavity and a plurality of openings continuous to the cavity, and a transmission line rotatably incorporated in the cavity of the stator and dividing the cavity between predetermined openings. and a rotor that is rotated to form a transmission path between a given combination of apertures and a different combination of apertures; A waveguide switching device characterized in that vertical and horizontal slots are provided in a leakage transmission path between two transmission paths formed by a gap provided between an outer wall of a rotor and an inner wall of a stator.