JPH04172701A - Separation/selection device for polarized wave signal - Google Patents

Abstract

PURPOSE:To eliminate the need for a long waveguide, to reduce the cost and the power consumption by providing an orthogonal mode converter and a mode selector on the device, and combining a power distributer and a hybrid coupler for the mode selector so as to form it as an electronic circuit. CONSTITUTION:A horizontal polarized wave component H of an input polarized wave signal received by an antenna is detected by a 1st probe 28a of an orthogonal mode converter 20, amplified by a low noise amplifier 22a and fed to an H input terminal (1) of a mode selector 24. A vertical polarized wave component V is detected by a 2nd probe 28b of the orthogonal mode converter 20, amplified by a low noise amplifier 22b and fed to a V input terminal (4) of the mode selector 24. The mode selector 24 consists of two Wilkinson type power amplifiers 32a, 32b distributing each input to two outputs respectively and a hybrid ring 34 receiving one of both distributed polarized wave components and synthesizing the phase and the amplitude respectively and the input signal is separated into a horizontal polarized wave, a vertical polarized wave, a right rotatory circularly polarized wave and a left rotatory circularly polarized wave by distributing the amplified both the signals and synthesizing the phase and the amplitude.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention provides an antenna and an LNB (Low Noise Block Down
The present invention relates to a device that is installed between the antenna (converter) and separates and selects horizontal and vertically polarized signals and right-handed and left-handed circularly polarized signals received by an antenna.

[Prior Art] Satellite communication individual reception services use linear polarization, while satellite broadcast reception services use circular polarization. In order to receive these polarized signals, it is usually necessary to provide a polarized signal separation and selection device called a polarization plane switcher before the LNB.

A conventional polarization plane switching device is realized by a combination of a phase plate 10 and a Faraday rotator 12, for example, as shown in FIG. The phase plate IO is a dielectric plate that produces a 90° phase difference, and the Faraday rotator 12 is a ferrite rod 14.
A coil 16 is arranged around the . These are incorporated into the waveguide 18 and provided between the antenna and the LNB. The received circularly polarized wave is converted into a linearly polarized wave by inserting a 90° phase plate lO in a direction of 45° with respect to the incident electric field. The Faraday rotator 12 changes the Faraday rotation angle by controlling the current flowing through the coil 16 to select a polarization mode. The signal is extracted by a waveguide to coaxial converter (not shown).

[Problems to be Solved by the Invention] However, the conventional polarization plane switching device as described above has the disadvantage that the length of the waveguide is large (for example, about 6.8 cm) and the weight is large. Furthermore, because it has a large number of parts and a complex structure that requires strict processing and assembly precision, it is not suitable for mass production and increases manufacturing costs. Furthermore, since current must continue to flow through the coil at all times, power consumption is also large.

SUMMARY OF THE INVENTION An object of the present invention is to provide a polarization signal separation/selection device that eliminates the above-mentioned drawbacks of the prior art and can be made smaller, lighter, and less expensive and consumes less power.

[Means for Solving the Problems] The present invention, which can achieve the above objects, includes an orthogonal moat converter that separately detects horizontal polarization components and vertical polarization components of an input polarization signal, and This is a polarization signal separation and selection device that includes an amplifier that amplifies each wave component, and a mote selector that receives the amplified both wave components as input.

Here, the mode selector consists of a power divider that divides each of the input partial wave components into two outputs, and a 90° hybrid direction that inputs either one of the distributed partial wave components and synthesizes the phase and amplitude. Consists of sexual couplers. Further, a switch means for switching the output signal from the mode selector is provided.

[Operation] The orthogonal mode converter separately detects the horizontal polarization component and the vertical polarization component of the input polarization signal, and the amplifier amplifies each polarization component. Each power divider divides each polarization component into two outputs.

In the case of horizontally polarized waves and vertically polarized waves, they are output from each power divider as they are. In the case of circularly polarized waves, a 90° hybrid directional coupler combines the phases and amplitudes of both wave components to output right-handed circularly polarized waves and left-handed circularly polarized waves.

[Embodiment] FIG. 1 is a block diagram showing an embodiment of a polarization signal separation and selection device according to the present invention, and FIG. 2 is a block diagram showing an example of a mode selector thereof.

This device includes an orthogonal mode converter 20 that separately detects horizontal polarization components and vertical polarization components of a polarization signal received by an antenna (not shown), and amplifies both detected components. horizontally polarized wave by the low noise amplifiers 22a and 22b, distribution of both amplified signals, and synthesis of phase and amplitude.
It is equipped with a mode selector 24 that separates signals into vertically polarized waves, right-handed circularly polarized waves, and left-handed circularly polarized waves.

The orthogonal mode converter 20 includes two probes 28a in the waveguide 26 so as to be orthogonal to each other.

28b is arranged. Since FIG. 1 is a schematic drawing, both probes 28a and 28b are oriented in the same direction, or are actually arranged so as to be orthogonal to each other.

The length of this waveguide 26 is approximately 2 cm. Here, a moat filter 30 is inserted between both probes 28a and 28b. This mode filter 30 functions to block horizontally polarized components. Each coaxial terminal of the quadrature moat converter 20 is connected to the input end of a low noise amplifier 22a, 22b, respectively. The low-noise amplifiers 22a and 22b are GaA low-noise HEMTs (child mobility transistors).
s (gallium-arsenide) device. The output of each low noise amplifier 22a, 22b is . Mode selector 24
connected to each input terminal of

The mode selector 24 includes two Wilkinson type power dividers 32a and 32b that divide each input into two outputs.
and a hybrid ring 34 which inputs one of the distributed two-part wave components and synthesizes the phase and amplitude.

These are MMICs (monolithic microwave integrated circuits)
Consists of. Therefore, the power divider 32a.

32b uses a planar Y-shaped power divider.

The hybrid ring 34 is a 90° hybrid directional coupler with two power branches and two output branches, and the microwave input from one input branch does not appear at the other input branch, and the two output branches are mutually connected. Phase or 90° (π/
2) It has the characteristic of outputting with a deviation. Both power dividers 32a,
One of the two outputs of the 32b is a hybrid/
It is connected to two power branches of the ring 34, and the other of the two outputs is output as is. Mode selector 2
These four types of output signals (horizontal polarization signal H
1, right-handed circularly polarized signal R1, left-handed circularly polarized signal L1, and vertically polarized signal V) are switched by an external control signal by the subsequent switch means 36 and output to the LNB (not shown).

Next, the operation of this device will be explained. The horizontal polarization component H of the input polarization signal received by the antenna is detected by the first probe 28a of the orthogonal mode converter 20, and the weak signal is amplified to an appropriate level by the low noise amplifier 22a. It is applied to the H input terminal (3) of the mode selector 24. The vertically polarized wave component V is detected by the second probe 28b, and similarly, the weak signal is reduced to an appropriate level by the low noise amplifier 22.
After being amplified by b, the signal is applied to the V input terminal (2) of the mode selector 24.

If we consider the case where a horizontal linear polarized wave is received, a signal appears at the H input terminal (3) of the mode selector 24. This signal is divided by the power divider 32a, and the signal at one terminal (2) is directly output to the H output terminal (2). When receiving vertically linearly polarized waves, a signal appears at the V input terminal (3) of the mode selector 24. This signal is divided by the power divider 32b, and the signal at one terminal (2) is output as is to the V output terminal 0.

Next, when a right-handed circularly polarized wave is received, this right-handed circularly polarized wave can be considered to be a combination of linearly polarized waves in which the vertically polarized wave component leads the horizontally polarized wave component by a phase of π/2.

Therefore, the H input terminal ■ and the V input terminal ■ of the mode selector 24
is added with a phase difference of π/2. First, look at the signal applied to the V input terminal ■. If the phase of the horizontal polarization component is 0,
Since the power is distributed by the power divider 32b and the phase is delayed by π/2, the phase becomes 0 at the terminal ■. This signal is applied to the hybrid ring 34, and a signal delayed by π appears at its R output terminal ■, and a signal whose phase is delayed by π appears at its L output terminal ■.
A signal delayed by /2 appears. Also, looking at the signal applied to the H input terminal (2), since it is distributed by the power divider 32a and the phase is delayed by π/2, the phase at the terminal (2) is 1π/2.

This signal is applied to the hybrid ring 34, and a signal delayed by π/2 from the phase appears at its R output terminal ■, so the delayed phase as a whole is π, and at its L output terminal ■, the phase is delayed by π/2. Since only a signal delayed by 100 min appears, the overall delayed phase is 3π/2. When the above vertically polarized wave component and horizontally polarized wave component are combined, both wave components have the same phase at the R output terminal ■, so a summed output is generated, but the L
At the output terminal (■), both partial wave components have opposite phases, so they cancel each other out and no signal appears.

When a left-handed circularly polarized wave is received, the above is reversed, and an output is generated at the L output terminal (2), but no signal appears at the R output terminal (2) because both partial wave components cancel each other out.

In the end, by switching the output signals of the respective output terminals (1) to (1) to [phase] using the switch means 36, a desired signal among the signals received by the antenna can be coupled to the LNB.

[Effects of the Invention] As described above, the present invention consists of an orthogonal mode converter and a mode selector, and the mode selector is configured as an electronic circuit by combining a power divider and a hybrid coupler. This eliminates the need for long waveguides. In the present invention, since the electronic circuit can be made into an MMIC, it becomes possible to reduce the size and weight, which are fundamentally important in antenna reception, and it can be mass-produced at low cost.In addition, since a coil is not required as in the conventional technology, power consumption is also reduced. .

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a polarization signal separation and selection device according to the present invention, and FIG. 2 is a block diagram showing an example of a mode selector thereof. Further, FIG. 3 is an explanatory diagram showing an example of the prior art. 20... Orthogonal mode converter, 22a, 22b... Low noise amplifier, 24... Mode selector, 28a528b
...Probe, 32a, 32b...Power divider, 3
4...Hybrid ring, 36...Switch means.

Claims (2)

[Claims] 1. An orthogonal mode converter that separately detects horizontal and vertical polarization components of an input polarization signal, an amplifier that amplifies each of the detected polarization components, and an input terminal that receives the amplified polarization components. The mode selector is equipped with a power divider that divides both input polarization components into two outputs, and a power divider that divides each of the input polarization components into two outputs, and a power divider that divides the input polarization components into two outputs, and a power divider that divides the input polarization components into two outputs. A polarization signal separation and selection device comprising a 90° hybrid directional coupler for combining. 2. 2. The apparatus according to claim 1, further comprising switch means for switching the output signal from the mode selector.