JPH04207601A - Circularly/linearly polarized wave converter - Google Patents

Abstract

PURPOSE:To improve the axis ratio of a circularly polarized wave by arranging two probes apart by lambdag/4 (lambdag is a guide wavelength) along the axis direction of a waveguide while they are observed at positions different by 90 deg. from the opening of the waveguide. CONSTITUTION:Both probes 28, 30 are arranged to a state that they are observed at different positions by 90 deg. from an opening 24 of a waveguide 22 and apart by lambdag/4 (lambdag is a guide wavelength) along the axial direction of the waveguide 22. Then both, the probes 28, 30 are connected by a line through which a signal of the same phase and the same amplitude is supplied. Since the two probes 28, 30 are arranged by lambdag/4 in the guide axis direction to the waveguide 22, when a linearly polarized signal is fed to the line, signals with different phases by 90 deg. are fed respectively to the two probes 28, 30. Moreover, the two probes 28, 30 have an angle of 90 deg. when viewing from the opening 24 of the waveguide 22 and a circularly polarized radio wave is generated from the opening 24 of the probes 28, 30. Thus, the axial ratio of the circularly polarized wave is improved.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a circular polarization system used to convert circularly polarized waves into linearly polarized waves, and conversely, to convert linearly polarized waves into circularly polarized waves. Regarding linear polarization converters.

(Prior Art) Conventionally, as the above-mentioned circular-linear polarization converter, for example, as shown in "Introduction to Satellite Broadcasting Reception", published by Japan Broadcasting Corporation, edited by Japan Broadcasting Corporation, page 103, Some had a phase plate inserted inside the waveguide along its length.

Further, as shown in FIG. 5, a dielectric plate 4 is inserted into the waveguide 2 at right angles to the tube axis direction of the waveguide 2, and a
Two probes 6.8 are installed at an angle of 90 degrees, and when converting circularly polarized waves to linearly polarized waves, the ultra-high frequency signals received by the two probes 6.8 are separated by 90 degrees. Combine with phase difference.

This synthesis is performed by providing a 90 degree phase shifter between the two probes. Note that the waveguide 2 of the dielectric plate 4
A converter 10 for converting the synthesized ultra-high frequency signal to a lower frequency is formed in a portion protruding from the top. 12 is a case surrounding the converter 10.

[Problem to be solved by the invention]

However, in the case where a phase plate is provided, the length of the waveguide 2 must be increased in order to provide the phase plate, which poses a problem in that the length of the circular-to-linear polarization converter also becomes longer.

Furthermore, in the one shown in FIG. 5, the dielectric plate 4 is
Since it is perpendicular to the waveguide 2, as shown in FIG.
The problem is that the circular-to-linear polarization converter and the converter 10 must be placed at an angle, resulting in poor design. Further, since this requires the use of a phase shifter, there is a problem that the power distribution to the two probes 6.8 is not equal and the axial ratio of the circularly polarized waves is poor.

An object of the present invention is to provide a circular-linear polarization converter that solves each of the above-mentioned problems.

[Means to solve the problem]

In order to solve the above problems, the present invention provides a circular waveguide, a substrate provided inside the circular waveguide obliquely with respect to the tube axis direction, and at least one substrate provided on the substrate. It has two probes. The two probes are positioned at 90 degrees different positions when viewed from the opening of the waveguide, and the probes are aligned at λg/4 (λg is They are located at different wavelengths (intra-tube wavelength). Above this, both probes are coupled by a line that supplies signals of the same phase and amplitude to both probes.

[Effect]

According to the present invention, since the two probes are located apart from each other by λg/4 in the tube axis direction of the waveguide, when a linearly polarized signal is supplied to the line, the two probes receive a signal of 90
Signals with different degrees of phase are supplied. Further, the two probes are at an angle of 90 degrees when viewed from the opening of the waveguide. Therefore, circularly polarized radio waves can be generated from the opening of the waveguide.

〔Example〕

The circular-linear polarization converter 20 of this embodiment has a circular waveguide 22, as shown in FIG. 1, and a horn portion 24 is provided at the opening of the circular waveguide 22.

A portion of a substrate 26 with low dielectric loss, such as a Teflon substrate, a foamed polyethylene plate, or a polyester substrate, is inserted into the waveguide 22 so as to form an acute angle φ with respect to the tube axis.

Two probes 28 and 30 are provided in the portion of the substrate 26 that is inserted into the waveguide 22.

As shown in FIG. 2, these probes 28.30 are positioned so that the two probes 28.30 are separated by an angle of 90 degrees when viewed from the opening of the waveguide 22. As shown in FIG. 3, the angle θ is wider than 90 degrees. Moreover, these probes 28 and 30 are arranged along the tube axis direction of the waveguide 22 by λg/4(
λg are spaced apart from each other by an amount (internal wavelength) of the radio waves to be converted from circularly polarized waves to linearly polarized waves by the circular-to-linearly polarized wave converter 20. The probes 28.30 are also coupled to each other via lines 32.34 having the same length and width dimensions.

Further, in a portion of the substrate 26 protruding from the waveguide 22, a signal of, for example, a 12 GH band, which has been converted from a circularly polarized wave to a linearly polarized wave by the circular-linear polarized wave converter 20, is connected to, for example, an I GH band.
A converter 36 for converting the signal into a Z-band signal is provided as shown by the dotted line in FIG. Of course, the input side of this converter 36 is connected via a line 38 to a node 35 of lines 32, 34 shown in FIG.

Further, the protruding portion of the board 26 is covered by a case 40 as shown in FIG. Since this case 40 is provided along the length direction of the substrate 26, it forms an acute angle with respect to the waveguide 22.

An arm 42 extending along the length of the case 40 is provided at the lower end of the case 40, and the arm 42 is coupled to a mounting portion 46 provided on the back side of the offset parabolic reflector 44. . Of course, the circular-linear polarization converter 20
The horn portion 24 is located at the focal point of the reflecting mirror 44.

In the circular-linear polarization converter 20 configured in this way, signals are supplied to the probe 28.30 via the lines 32.34 having the same width and length.
The signals supplied to the probes 28, 30 are of the same amplitude and phase. Since the probes 28.30 are located apart from each other by λg/4 in the tube axis direction, signals having a phase difference of 90 degrees are ultimately supplied to the probes 28.30. The probes 28, 30 are also spaced apart by 90 degrees when viewed from the opening of the waveguide 22. Therefore, when viewed from the opening of the waveguide 22, the probe 28.30
are supplied with signals having a phase difference of 90 degrees, and the probes 28 and 30 are mechanically arranged 90 degrees apart, so that if a linearly polarized signal is supplied to the coupling point 35, , a circularly polarized signal is obtained from the opening of the waveguide 22. Note that the above explanation deals with converting a linearly polarized wave into a circularly polarized wave, but when a circularly polarized radio wave is supplied to the horn section 26, the coupling point 35 is converted by an operation opposite to the above. Needless to say, a linearly polarized signal can be obtained.

In the embodiments described above, two probes 28, 30 are provided, or another probe is provided at a position separated by an angle of 180 degrees from the probe 28, and a signal having a phase different from the probe 28 by 90 degrees is supplied to this probe. Another probe may be provided at a position ζ6 which is 180 degrees different from the probe 30, and a signal having a phase different from the probe 30 by 90 degrees may be supplied to this probe.

Further, probes are provided independently, perpendicular to the tube axis of the waveguide, and separated by λg/4 in the tube axis direction,
These two probes may be powered by a flat substrate. Further, for these two probes, a coupling probe may be provided outside the waveguide, and this coupling probe may be coupled outside the waveguide by another waveguide.

〔Effect of the invention〕

As described above, according to the present invention, since the substrate can be provided in the waveguide obliquely with respect to the tube axis of the waveguide, the circularly-linearly polarized wave according to the present invention can be provided in the same straight line as the substrate. An arm can be placed to support the transducer, resulting in a better design. Furthermore, since signals are supplied to the two probes or signals are received from the two probes via lines having the same width and length, the axial ratio of the circularly polarized waves is good.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of an embodiment of a circular-linear polarization converter according to the present invention, FIG. 2 is a front view of the embodiment, and FIG. 3 is a plan view of a substrate used in the embodiment. Figure 4 is a side view of a parabolic antenna using the circular-to-linear polarization converter of the same embodiment, Figure 5 is a longitudinal cross-sectional view of a conventional circular-to-linear polarization converter, and Figure 6 is a diagram of the same as in Figure 5. FIG. 2 is a side view of a parabolic antenna using a circular-to-linear polarization converter. 22... Waveguide, 26... Substrate, 28.30...
Probe, 32.34...railway. Patent applicant: DX Antenna Co., Ltd. Representative: Satoshi Shimizu and 2 others 1. Zusuke 2 (2) Ryo 3. Ryō Liang 412 No. 5 [2]

Claims (1)

[Claims] (1) It has a circular waveguide, a substrate provided in the circular waveguide obliquely with respect to the tube axis, and at least two probes provided on the substrate, and the probe is , when viewed from the opening of the waveguide, the probes appear to be at different positions by 90 degrees, and the probes are spaced apart by λg/4 (λg is the wavelength within the guide) along the axial direction of the waveguide. A circular-to-linear polarization converter, characterized in that both probes are coupled by a line that supplies signals of the same phase and amplitude to both probes.