JPS5854701A - Waveguide-microstrip line converter - Google Patents

Abstract

PURPOSE:To attain excellent coupling with both vertical and horizontal polarized waves, by providing a strip line antenna and a resonance window in a waveguide. CONSTITUTION:A polarized wave in parallel with a short axis of a resonance window can tramsmit a resonance window, but a polarized wave in parallel with a long axis cannot trasmit, and is reflected, because the resonance window shows a large reactance. The V wave is reflected at the 1st resonance window and absorbed by an antenna provided to a microstrip base 15. The H wave is orthogonal to the antenna provided to the base 15 and has the polarized wave in the direction of the short axis of the 1st resonance window, then the wave transmits the 1st resonance window. After the H wave is absorbed by the antenna provided to the 2nd microstrip base 16, the wave is also reflected at the 2nd resonance window and absorbed by the antenna.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to microwave circuits, and more particularly to circular waveguide and microstrip line transducers.

Generally, in microwave devices that require low loss, connections to external circuits such as antennas are made using waveguides.

Further, the signal processing circuit inside the device is composed of a microstrip line circuit.

Therefore, a waveguide-coaxial converter and a coaxial-microstripline converter are required between the waveguide and the signal processing circuit. That is, the coaxial terminal side of the waveguide-coaxial converter and the terminal of the signal processing circuit (microstrip line) were connected via a coaxial plug.

As shown in Figure 1, the waveguide-coaxial converter with the
and, in some cases, a stub screw 4 for adjustment. For example, in the case of a microwave receiving device using a parabolic antenna or the like, the primary radiator of the parabolic antenna requires structural symmetry, so a circular waveguide or the like is often used. Therefore, conventionally, in this type of receiving device, the second
As shown in the figure, a circular waveguide-to-rectangular waveguide converter 6 is also required between the waveguide-to-coaxial converter 4 and the parabolic antenna radiator 5. Note that 7 is a signal processing circuit including a strip line. Conventional microwave devices have the drawbacks of having a large number of component parts, being large and complex, making them unsuitable for mass production, and requiring high manufacturing costs.

An object of the present invention is to eliminate these drawbacks and provide a waveguide-stripline converter that is small, easy to mass produce, and has high performance.

According to the present invention, there is provided a microstrip line extended within a circular waveguide capable of transmitting a plurality of polarized waves, and a microstrip line whose polarization plane is orthogonal to the strip line within the waveguide.
By having a resonant window placed approximately 1/4 wavelength away from the J-tube line, it is simple, compact, suitable for mass production, and allows vertically polarized waves (hereinafter abbreviated as V-waves) of the external waveguide. ) and horizontally polarized waves (hereinafter abbreviated as H waves) can be obtained.

The invention will now be described in detail with reference to the drawings of embodiments of the invention. FIG. 3 shows a first embodiment of the present invention, in which a circular waveguide 10. Resonant window 11. It includes a microstrip line board 12 and an antenna 13 extending from the microstrip line board 12. The substrate 12 includes a signal processing circuit. In Figure 3,
The views seen from directions A, B, and C are shown in Figure 4. Fifth. 6th
It is shown in the figure. In FIG. 4, the antenna 13 is arranged parallel to the V wave in this example so as to selectively absorb the coupled desired wave. A matching section 14 may be provided on the stripline to improve the matching between the waveguide and the stripline.

Next, before explaining the present invention in detail, the operation of the resonant window 11 will be explained. FIG. 7 is a diagram explaining the operation of the resonance window. The equivalent circuit of the resonant window differs depending on the polarization direction of the incident wave. That is, in the resonant window shown in FIG. 7(a), the equivalent circuit for polarized waves parallel to the short axis of the resonant window, that is, in the Y direction in the same figure, is shown in FIG. 7(b). If the length L of the long axis of the resonant window is selected to be approximately 1/2 wavelength, the resonant frequency of the equivalent circuit shown in FIG. 7(b) can be made the same as the operating frequency. Therefore, the polarized wave in the Y direction can pass through the resonance window. In contrast, the equivalent circuit of the resonant window for polarized waves in the X direction in FIG. 7(a) is shown in FIG. 7(C).

That is, for polarized waves in the X direction, the resonant window has a large susceptance and actance, and the polarized waves in the 9X direction are reflected by the resonant window and cannot pass through the n1 resonant window. Therefore, in FIG. 5, the V wave that enters from the incident direction shown in the figure is absorbed by the antenna 13, and since this vt& is parallel to the long axis direction of the resonant window, it is blocked by the resonant window. n, the propagation is blocked, n1 is reflected, and it is not effectively absorbed by the antenna. Since the H wave is orthogonal to the antenna 13,
It is not absorbed by the antenna, and furthermore, because it is parallel to the short axis of the resonance window, it passes through the resonance window.

The above explanation has been given for an example in which the external waveguide and the present converter are coupled by ■ waves. By shifting the connection between this converter and the external waveguide by 90 degrees around the waveguide axis, it is also possible to couple the external waveguide's (wave) with this converter. Therefore, this converter and one For example, in the example of FIG. 8, the first and second transducers, which are exactly the same, are connected at 90 degrees offset from each other around the axis as shown in FIG. a microphone 5 that simultaneously couples the V and H waves, such that the second transducer 16 couples the V waves and the H waves;
− It is also possible to easily configure the wave device.

In the embodiment shown in FIG.
were arranged perpendicular to the central axis of the circular waveguide, but in Fig. 9 (a
), As shown in (b), the microstrip line substrate 20 is placed parallel to the axis of the circular waveguide 21! ! i2 place 1
．． It is clear that similar effects can be obtained with 2.

A similar effect can be obtained by using other waveguides capable of simultaneously transmitting orthogonal mode waves, such as a waveguide with a square cross section, in place of the circular waveguide described above.

As described above, the circular waveguide-microst IJ tube line converter according to the present invention is small and lightweight, suitable for mass production, and can constitute a microwave device with good performance.

As explained above, the present invention has a simple configuration in which the antenna is constructed using a strip line board and a resonant window is used, which is compact, lightweight, easy to mass produce, has good performance, and can couple both H waves and V waves. There is an effect that can be done.

−6=

[Brief explanation of the drawing]

Fig. 1 shows a conventional waveguide-coaxial converter, Fig. 2 shows a circular-rectangular converter conventionally used in parabolic antennas, etc., and Fig. 3 shows a conventional waveguide-coaxial converter. Figure 4 showing one embodiment. Fifth. FIG. 6 shows A, B, and B shown in FIG. 3, respectively.
View from direction C, Figure 7 (a), (b),
(C) is a diagram explaining the operation of the resonator, Figure 8 is a V wave,
Connection configuration diagram for simultaneous coupling to I-1 wave, Figure 9 (a)
, (b) is a front view and a side view showing another embodiment of the present invention. \. 7-21 Figure 2 Figure ρ z ,,3 Figure 3- ((1) tb)
7 Figure f5' Figure 2 ρ tO) Z q Figure (Cn Suku 2 anti 2〃 (b) 4-

Claims (1)

[Claims] a waveguide capable of transmitting a plurality of polarized waves; a microstrip line extending within the waveguide; and a polarization coupled to the microstrip line at a predetermined position away from the microstrip line within the waveguide. A waveguide-microstrip line converter comprising: a plate having a resonant window in which the wave direction is the longitudinal direction.