JPS625534B2 - - Google Patents

Description

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

Generally, in microwave equipment that requires low loss,
Connections to external circuits such as antennas are made through 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, this waveguide-coaxial converter consists of a waveguide 1 and an antenna 2 made of a metal rod.
, a coaxial plug 3 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, in conventional receiving devices of this type, the second
As shown in the figure, a circular waveguide-rectangular waveguide converter 6 was further required between the waveguide-coaxial converter 4 and the parabolic antenna radiator 5. Note that 7 is a signal processing circuit including a stripline. 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.

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

According to the present invention, there is provided a microstripline extended in a circular waveguide capable of transmitting a plurality of polarized waves, and a microstripline whose polarization plane is orthogonal to the stripline within the waveguide and approximately 1/2 By being equipped with resonant windows placed 4 wavelengths apart, it is simple, compact, and suitable for mass production. A waveguide-to-stripline converter is obtained which can also be coupled to the

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 invention, which includes a circular waveguide 10, a resonant window 11, a microstripline substrate 12, and an antenna 13 extended therefrom. The substrate 12 includes a signal processing circuit. In FIG. 3, views seen from directions A, B, and C are shown in FIGS. 4, 5, and 6, respectively. 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 operation of the present invention, the resonant window 1
The operation of step 1 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. 7a, 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. 7b. The length L of the long axis of the resonant window is approximately 1/
If two wavelengths are selected, the resonance frequency of the equivalent circuit shown in FIG. 7b can be made the same as the operating frequency.
Therefore, the polarized wave in the Y direction can pass through the resonance window. On the other hand, the equivalent circuit of the resonant window for polarized waves in the X direction in FIG. 7a is shown in FIG. 7c. That is, for polarized waves in the X direction, the resonant window becomes a reactance with a large susceptance, and the polarized waves in the X direction are reflected by the resonant window and cannot pass through the 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 V wave is parallel to the long axis direction of the resonance window, it is blocked by the resonance window. Being done,
It is blocked, reflected and effectively absorbed by the antenna. Since the H wave is perpendicular to the antenna 13, it is not absorbed by the antenna, and since 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 V waves. If the connection between this converter and the external waveguide is shifted by 90 degrees around the waveguide axis, the H wave of the external waveguide and this converter can be coupled. Therefore, if the first and second converters, which are exactly the same as this converter, are connected to each other with their axes shifted by 90 degrees as shown in FIG. A microwave device that combines V waves and H waves at the same time can be easily constructed by combining V waves with the second converter 15 and H waves with the second converter 16. You can also do that.

In the embodiment shown in FIG. 3, the microstrip substrate 12 is arranged perpendicular to the central axis of the circular waveguide.
It is clear that the same effect can be obtained even if the microstripline substrate 20 is arranged parallel to the axis of the circular waveguide 21, as shown in FIGS. 9a and 9b.

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-microstripline 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 uses a stripline board to configure the antenna, and by using a resonant window, a simple configuration that is small, lightweight, easy to mass produce, has good performance, and couples both H and V waves can be achieved. effective.

[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 an embodiment of the present invention. Figures showing examples; Figures 4, 5, and 6 are views seen from directions A, B, and C shown in Figure 3, respectively; Figures 7 a, b, and c explain the operation of the resonator. Figures 8 and 8 are connection configuration diagrams for simultaneously coupling V waves and H waves, and Figures 9a and 9b are front and side views showing other embodiments of the present invention.

Claims (1)

[Claims] 1. A waveguide capable of transmitting multiple polarized waves, a microstrip line extended within the waveguide,
and a plate having a resonant window in which the direction of polarized light coupled to the microstrip line is in the longitudinal direction at a position apart from the microstrip line by a predetermined position within the waveguide. Wave tube-microstripline converter.