Receiving device

Abstract

The present invention provides a reception device comprising: an electric-photo conversion circuit that converts a received signal in a direction of each of rows forming a two-dimensional array into an optical signal at a unique frequency; a first scan matrix circuit that phase-weights, for first-axis scan, the optical signals obtained by optical wavelength-multiplexing; an optical frequency conversion circuit that converts the frequencies of the optical signals divided into optical frequencies so that the optical signals have the same frequency; and a second scan matrix circuit that phase-weights, for second-axis scan, the optical signals obtained by the conversion of the frequencies.

Description

[Technical Field]

[0001] The present invention relates to a receiving device for wireless communication. [Background technology]

[0002] As a receiving device for wireless communication, a circuit that performs beam control corresponding to both two-dimensional beam scanning and multi-beam scanning has been developed. For example, Non-Patent Document 1 discloses a technology that uses passive phase shift circuits such as Butler matrices, Blass matrices, etc., stacked four circuits horizontally and stacked four circuits vertically in combination. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] H. Liu, X. Liu, F. Effenberger, N. Chand, X. Qi and G. Li, "Optical Implementation of Butler Matrix for Hardware-Efficient Multiuser Beamforming," in IEEE Photonics Journal, vol. 10, no. 2, pp. 1-8, April 2018. Summary of the Invention [Problem to be solved by the invention]

[0004] The beam control circuitry in the above-mentioned conventional technology that supports both two-dimensional beam scanning and multi-beam scanning requires a three-dimensional wiring structure, which makes it impossible to reduce the height of the receiving device and makes it unsuitable for mass production using printed circuit manufacturing processes.

[0005] The disclosed technology aims to realize a low-profile receiving device. [Means for solving the problem]

[0006] The disclosed technology is a receiving device that includes an optoelectronic conversion circuit that converts received signals in each row direction that constitutes a two-dimensional array into optical signals of different frequencies, a first scanning matrix circuit that applies phase weighting to the optical wavelength-multiplexed optical signals for first-axis scanning, an optical frequency conversion circuit that converts the frequencies of the optical signals that have been demultiplexed by optical frequency to align them to the same frequency, and a second scanning matrix circuit that applies phase weighting to the frequency-converted optical signals for second-axis scanning. [Effects of the Invention]

[0007] The height of the receiving device can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a conventional receiving device. [Figure 2] FIG. 1 is a diagram illustrating an example of the configuration of a receiving device according to a first embodiment of the present invention. [Figure 3] FIG. 10 is a diagram illustrating a configuration example of a receiving device according to a second embodiment of the present invention. [Figure 4] FIG. 10 is a diagram illustrating a configuration example of a receiving device according to a third embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating a configuration example of a receiving device according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention (the present embodiment) will be described with reference to the drawings. The embodiment described below is merely an example, and the embodiment to which the present invention is applied is not limited to the following embodiment.

[0010] (Previous problems) First, the problems of the conventional technology will be described.

[0011] Figure 1 shows an example of the configuration of a conventional receiving device. The conventional receiving device receives incoming radio waves using a 4x4 array antenna. Each photoelectric conversion circuit connected to each array antenna consists of a light source and an optical modulator. Each photoelectric conversion circuit converts the radio waves received by each array antenna into light.

[0012] The receiver changes the phase of light for each axis using a circuit consisting of four horizontally stacked phase-shifting circuits (phase-shifting circuit for second-axis scanning) and four vertically stacked phase-shifting circuits (phase-shifting circuit for first-axis scanning), each of which uses passive phase-shifting circuits such as Butler matrices and Blass matrices.The receiver then controls the directionality of the received signal by controlling a two-dimensional path changeover switch according to the beam index of the desired direction of reception.

[0013] However, in such conventional receiving devices, the beam control circuitry compatible with two-dimensional beam scanning and multi-beams requires a three-dimensional wiring structure, which makes it impossible to reduce the height of the receiving device and makes it unsuitable for mass production using printed circuit manufacturing processes.

[0014] (Outline of this embodiment) In order to solve the above-mentioned problems of the conventional art, in this embodiment, a method will be described in which the number of matrix circuits included in the receiving device is reduced to one for each axis, and the phase shift circuit is made planar.

[0015] Hereinafter, examples 1 to 4 will be described as specific examples of this embodiment.

[0016] Example 1 In this embodiment, an example will be described in which the received signals of each row-direction one-dimensional array that constitutes a two-dimensional array are converted into optical signals of different frequencies for each element, combined (wavelength multiplexed), phase-weighted for first-axis scanning, demultiplexed according to optical frequency, all optical signals are aligned to the same frequency, phase-weighted for second-axis scanning, and the received signals are output.

[0017] 2 is a diagram illustrating a configuration example of a receiving device according to Example 1 of an embodiment of the present invention. The receiving device 1 includes a plurality of antenna elements 10, a plurality of photoelectric conversion circuits 20, a vertical scanning matrix circuit 30, a vertical scanning changeover switch 40, an optical frequency conversion circuit 50, a horizontal scanning matrix circuit 60, and a horizontal scanning changeover switch 70.

[0018] The antenna elements 10 are arranged in, for example, a 4 x 4 array structure, and each antenna element 10 receives a radio signal.

[0019] Each of the photoelectric conversion circuits 20 included in the plurality of photoelectric conversion circuits 20 converts the radio signal received by each antenna element 10 into light. In other words, each photoelectric conversion circuit 20 modulates the light with the radio signal received by each antenna element 10. The modulated optical signal is optically wavelength-multiplexed for each row (ch1-ch4) by the multiplexer.

[0020] The vertical scanning matrix circuit 30 (first scanning matrix circuit) performs phase weighting for vertical (first axis) scanning. Among the output ports of the vertical scanning matrix circuit 30, the port with the maximum signal level is determined by the vertical direction in which the beam arrives. Therefore, the receiving device 1 uses the vertical scanning changeover switch 40 to select the port with the maximum signal level and connect it to the subsequent stage.

[0021] The optical signal output from the port selected by the vertical scanning selector switch 40 (first selector switch) is demultiplexed by optical frequency by a demultiplexer that switches paths for each wavelength. The optical frequency conversion circuit 50 aligns the optical frequencies of the four signals to ch1. Here, the optical frequency conversion circuit 50 converts each optical frequency so that the phase relationship between the four signals is maintained. The interval between the center frequencies of each channel is Δf.

[0022] The horizontal scanning matrix circuit 60 (second scanning matrix circuit) performs phase weighting for horizontal (second axis) scanning.

[0023] The receiving device 1 outputs the output of the terminal corresponding to the horizontal direction of the beam selected by the horizontal scanning selector switch 70 (second selector switch) as a received signal. Among the output ports of the horizontal scanning matrix circuit 60, the port with the maximum signal level is determined by the horizontal direction in which the beam arrives. Therefore, the receiving device 1 switches the wiring using the horizontal scanning selector switch 70 so that the port with the maximum signal level outputs the "received signal."

[0024] According to the receiver 1 of this embodiment, the received signals of each row-direction one-dimensional array constituting the two-dimensional array are converted into optical signals of different frequencies for each element, multiplexed (wavelength multiplexed), phase-weighted for first-axis scanning, demultiplexed according to optical frequency, aligned to the same frequency for all optical signals, phase-weighted for second-axis scanning, and output as the received signals. This allows the number of matrix circuits included in the receiver to be reduced to one per axis, and the phase-shift circuit to be planarized. In other words, the receiver can be made low-profile.

[0025] Example 2 A second embodiment will be described below with reference to the drawings. The second embodiment differs from the first embodiment in that the matrix circuit is reused by wavelength multiplexing. Therefore, the following description of the second embodiment will focus on the differences from the first embodiment, and components having the same functional configuration as the first embodiment will be assigned the same reference numerals as those used in the description of the first embodiment, and the description thereof will be omitted.

[0026] 3 is a diagram illustrating a configuration example of a receiving device according to Example 2 of the embodiment of the present invention. The receiving device 1 according to this example further includes a duplexer 80 in addition to the receiving device 1 according to Example 1. The receiving device 1 according to this example also includes one scanning matrix circuit 30. That is, the receiving device 1 does not necessarily have to include multiple scanning matrix circuits (vertical scanning matrix circuit and horizontal scanning matrix circuit).

[0027] The scanning matrix circuit 30 performs phase weighting for vertical scanning on the light modulated by the photoelectric conversion circuit 20, similar to the vertical scanning matrix circuit 30 according to the first embodiment.

[0028] The demultiplexer 80 demultiplexes the optical signal into a phase-weighted optical signal for vertical scanning and a phase-weighted optical signal for horizontal scanning, which will be described later, by frequency. The receiver 1 uses the vertical scanning selector switch 40 to select the port with the highest signal level and connects the phase-weighted light for vertical scanning to the subsequent stage. The signal is then demultiplexed by optical frequency by a demultiplexer that switches paths for each wavelength. The optical frequency conversion circuit 50 aligns the optical frequencies of the four signals. The optical frequency conversion circuit 50 converts each optical frequency so that the phase relationship between the four signals is maintained. The interval between the center frequencies of each channel is Δf.

[0029] Here, the optical frequency conversion circuit 50 according to this embodiment converts the frequency of all phase-weighted light for vertical scanning, including the light of ch1, so that ch1-ch4 can be distinguished from ch5, which will be described later.

[0030] The optical signal whose optical frequency has been converted is input as ch5 again to the scanning matrix circuit 30. The scanning matrix circuit 30 performs phase weighting for horizontal scanning on the light input as ch5.

[0031] The optical signal that has been subjected to phase weighting for horizontal scanning and that has been demultiplexed by the demultiplexer 80 is input to the horizontal scanning changeover switch 70 .

[0032] According to this embodiment, the matrix circuit is reused by wavelength multiplexing, which allows the configuration of the receiving device 1 to be further simplified.

[0033] Example 3 Hereinafter, a third embodiment will be described with reference to the drawings. The third embodiment differs from the first embodiment in that the matrix circuit is reused by polarization multiplexing. Therefore, the following description of the third embodiment will focus on the differences from the first embodiment, and components having the same functional configuration as the first embodiment will be assigned the same reference numerals as those used in the description of the first embodiment, and the description thereof will be omitted.

[0034] 4 is a diagram illustrating a configuration example of a receiving device according to Example 3 of the embodiment of the present invention. The receiving device 1 according to this example further includes a polarization separator 90 and a polarization converter 100 in addition to the components of the receiving device 1 according to Example 1. The receiving device 1 according to this example also includes one scanning matrix circuit 30. That is, the receiving device 1 does not necessarily have to include multiple scanning matrix circuits (vertical scanning matrix circuit and horizontal scanning matrix circuit).

[0035] The scanning matrix circuit 30 performs phase weighting for vertical scanning on the light modulated by the photoelectric conversion circuit 20, similar to the vertical scanning matrix circuit 30 according to the first embodiment.

[0036] The polarization separator 90 separates the optical signal into a phase-weighted optical signal for vertical scanning and a phase-weighted optical signal for horizontal scanning, which will be described later, based on the polarization of the light. For example, the optical signal phase-weighted for vertical scanning is a TM (Transverse Magnetic) polarized wave, and the optical signal phase-weighted for horizontal scanning, which will be described later, is a TE (Transverse Electric) polarized wave.

[0037] The receiver 1 uses the vertical scanning selector switch 40 to select the port with the highest signal level and connects the phase-weighted light for vertical scanning to the subsequent stage. The signal is then demultiplexed by optical frequency using a demultiplexer that switches paths for each wavelength. The optical frequency conversion circuit 50 aligns the optical frequencies of the four signals to channel 1. The optical frequency conversion circuit 50 converts each optical frequency so that the phase relationship between the four signals is maintained. The interval between the center frequencies of each channel is Δf.

[0038] The polarization converter 100 rotates the polarization of the light whose optical frequency has been converted (or the light of ch1) by 90 degrees, converting the TM polarization into TE polarization. The optical signal converted into the TE polarization is input again to the scanning matrix circuit 30 as ch5. The scanning matrix circuit 30 performs phase weighting for horizontal scanning on the light input as ch5.

[0039] The optical signal separated by the polarization separator 90 and weighted for horizontal scanning is input to the horizontal scanning changeover switch 70 .

[0040] According to this embodiment, the matrix circuit is reused by polarization multiplexing, which allows the configuration of the receiving device 1 to be further simplified.

[0041] Example 4 Hereinafter, a fourth embodiment will be described with reference to the drawings. The fourth embodiment differs from the first embodiment in that received signals are multiplexed into multiple beams. Therefore, the following description of the fourth embodiment will focus on the differences from the first embodiment, and components having the same functional configuration as the first embodiment will be assigned the same reference numerals as those used in the description of the first embodiment, and descriptions thereof will be omitted.

[0042] The receiving device 1 of this embodiment creates optical frequency channel groups equal to the number of beams to be multiplexed (hereinafter referred to as K), assigns them to each antenna element, weights them using a matrix circuit, converts the optical signal groups corresponding to each beam to the same frequency for each beam, and outputs a received signal for each beam.

[0043] In the first embodiment, the number of optical frequency channels in each group is four, and the total number of optical frequency channels required in the receiving device according to this embodiment is K×4.

[0044] Fig. 5 is a diagram showing an example of the configuration of a receiving device according to Example 4 of the embodiment of the present invention. Fig. 5 shows an example in which the number of beams K is 2, and ch1 to ch4 are used to form beam 1, and ch5 to ch8 are used to form beam 2.

[0045] The vertical scanning changeover switch 40 according to this embodiment selects the outputs of two ports out of the four outputs of the vertical scanning matrix circuit 30 and outputs them to one terminal.

[0046] Furthermore, the optical frequency conversion circuit 50 according to this embodiment converts the phase-weighted optical signals for vertical scanning into the same frequency for each beam.

[0047] Furthermore, the horizontal scanning changeover switch 70 according to this embodiment selects the outputs of two ports out of the four outputs of the horizontal scanning matrix circuit 60. As a result, two beams are output as reception signals.

[0048] According to this embodiment, the received signals are multiplexed into multiple beams, which makes it possible to realize a low-profile receiver in beam control compatible with multiple beams.

[0049] (Summary of the embodiment) This specification describes at least the receiving devices described in the following sections. (Section 1) an opto-electrical conversion circuit that converts the received signals in each row direction constituting the two-dimensional array into optical signals with different frequencies; a first scanning matrix circuit that applies phase weighting to the optical wavelength multiplexed optical signal for first axis scanning; an optical frequency conversion circuit that converts the frequencies of the optical signals demultiplexed according to optical frequency so that they are all the same frequency; a second scanning matrix circuit that performs phase weighting on the frequency-converted optical signal for second axis scanning; Receiving device. (Section 2) the first scanning matrix circuit and the second scanning matrix circuit are the same scanning matrix circuit, The optical signal processing device further includes a demultiplexer that demultiplexes the phase-weighted optical signal for the first axis scanning and the phase-weighted optical signal for the second axis scanning based on frequency. 2. A receiving device according to claim 1. (Section 3) the first scanning matrix circuit and the second scanning matrix circuit are the same scanning matrix circuit, a polarization separator that separates the phase-weighted optical signal for the first axis scanning from the phase-weighted optical signal for the second axis scanning based on polarization; a polarization converter that converts the polarization of the phase-weighted optical signal for the first axis scanning, 2. A receiving device according to claim 1. (Section 4) a first selector switch that selects a plurality of signals for each beam included in the received signal from the phase-weighted optical signals for the first axis scanning; a second selector switch that selects a plurality of signals for each beam from the phase-weighted optical signals for second axis scanning, the optical frequency conversion circuit converts the frequencies of the optical signals demultiplexed according to the optical frequencies so that the frequencies of the beams are the same. 2. A receiving device according to claim 1.

[0050] Although the present embodiment has been described above, the present invention is not limited to such a specific embodiment, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0051] 1. Receiving device 10 Antenna Elements 20 Photoelectric conversion circuit 30 Vertical scanning matrix circuit (scanning matrix circuit) 40 Vertical scanning switch 50 Optical frequency conversion circuit 60 Horizontal scanning matrix circuit 70 Horizontal scanning switch 80 duplexer 90 Polarization separator 100 Polarization converter

Claims

1. an opto-electrical conversion circuit that converts received signals in each row direction constituting the two-dimensional array into optical signals with different frequencies; a first scanning matrix circuit that applies phase weighting to the optical wavelength multiplexed optical signal for first axis scanning; an optical frequency conversion circuit that converts the frequencies of the optical signals demultiplexed according to optical frequency so that they are all the same frequency; a second scanning matrix circuit that performs phase weighting on the frequency-converted optical signal for second axis scanning; Receiving device.

2. the first scanning matrix circuit and the second scanning matrix circuit are the same scanning matrix circuit, The optical signal scanning device further includes a demultiplexer that demultiplexes the phase-weighted optical signal for the first axis scanning and the phase-weighted optical signal for the second axis scanning based on frequency.

2. The receiving device according to claim 1.

3. the first scanning matrix circuit and the second scanning matrix circuit are the same scanning matrix circuit, a polarization separator that separates the phase-weighted optical signal for the first axis scanning from the phase-weighted optical signal for the second axis scanning based on polarization; a polarization converter that converts the polarization of the phase-weighted optical signal for the first axis scanning, 2. The receiving device according to claim 1.

4. a first selector switch that selects a plurality of signals for each beam included in the received signal from the phase-weighted optical signals for the first axis scanning; a second selector switch that selects a plurality of signals for each beam from the phase-weighted optical signals for second axis scanning, the optical frequency conversion circuit converts the frequencies of the optical signals demultiplexed according to the optical frequencies so that the frequencies of the beams are the same.

2. The receiving device according to claim 1.

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