JP3522910B2 - Mobile SNG device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an SNG (Satellite News) for transmitting a video / audio signal of a television from a disaster site to a base station (broadcasting station) via a communication satellite. Gatheri
ng) A mobile SNG device that is capable of transmitting a video / audio signal of a television via the communication satellite while automatically tracking a communication satellite from a moving object such as a moving ship or an automobile. It is about. 2. Description of the Related Art SNG devices have been widely used for transmitting news materials in the field of broadcasting. However, the conventional one is a fixed station that uses a parabolic antenna having a diameter of 75 cm or more as an antenna, and fixes and transmits the antenna. More recently, experiments on satellite communication while moving by combining mechanical tracking with a parabolic antenna (for example, Sekine and Yoshino, "Research and Development on Mobile Satellite Communication (TV)", Television Society Technical Report, VO
L. 18, No. 45, pp. 31-36, Aug. 199
There is also a report 4). [0003] In SNG, it is necessary to use a high gain antenna having a small antenna half width in order to avoid interference with adjacent communication satellites. For this reason, in a conventionally used SNG device of a fixed station, a parabolic antenna having a diameter of at least 75 cm (half-width of about 2 degrees) is fixed by a rigid support base so as not to move even in a strong wind. On the other hand, a moving object S transmitted from a moving ship or car
SNG using conventional parabolic antenna for NG device
In order to apply the technology of the device, the machine tracking accuracy in the azimuth and elevation directions for pointing the antenna toward the communication satellite needs to be at least ± 1 degree or less, which uses the parabolic antenna described above. As long as it was difficult to realize. Further, since a communication satellite uses linearly polarized waves, a mobile SNG device requires not only tracking in the azimuth and elevation directions but also polarization tracking. When a parabolic antenna is used, polarization tracking is performed by mechanically rotating the primary feed horn, but there is a problem in tracking speed and the like. An object of the present invention is to solve the above technical problems and to realize a mobile SNG device capable of performing high-speed and stable tracking which has been difficult to realize until now. In order to achieve the above object, the present invention uses a planar array antenna composed of a plurality of sub-array antennas instead of a parabolic antenna, and controls the transmission phase of each sub-array antenna. By combining the electronic tracking and the conventional mechanical tracking, stable transmission is always possible from the moving body. According to this, especially with high-speed and high-precision electronic tracking compared to machine tracking, it copes with fine vibrations and shaking of the moving body, and machine tracking is coarse tracking for large changes in direction such as turning of the moving body. Therefore, the machine tracking mechanism of the present invention does not need the high accuracy required only in the case of machine tracking. In the present invention, as a polarization tracking means, at least one transmission sub-array antenna for polarization control is provided on the planar array antenna, and the transmission sub-array antenna for main polarization and the transmission sub-array antenna for polarization control are provided. From the main polarization direction when transmitting power at a distant place by controlling the transmission power of the polarization control transmission sub-array antenna at the same time as transmitting in the same direction in the satellite direction. The degree can be changed. Further, the inclination of the polarization is detected from the pilot signal received by the sub-array antenna having the polarization directions orthogonal to each other, and the polarization of the transmission wave is controlled based on the detection result of the inclination of the polarization. Like that. That is, in the mobile SNG device of the present invention, a plurality of sub-array antennas for transmission and reception are arranged on the same plane, and the directivity control to the communication satellite is controlled by both mechanical tracking and electronic tracking. An antenna, wherein the communication satellite is transmitted using a pilot signal transmitted from a base station via the communication satellite and received by at least three sub-array antennas not arranged on the same straight line among the plurality of sub-array antennas. , And controlling the phase of the power supplied to the plurality of sub-array antennas based on the detection result to control the directional direction toward the communication satellite by the electronic tracking. Mobile SNG
In the apparatus, the polarization direction of one sub-array antenna among the plurality of sub-array antennas is made orthogonal to the polarization direction of another sub-array antenna, and the one sub-array antenna and the other sub-array antenna are orthogonal to each other. The one sub-array antenna and the other sub-array antenna, based on the polarization tilt angle of the arriving wave detected between the pilot signals received by any one of the antennas. By controlling the ratio of the transmission power supplied to each of them, the polarization inclination angle of the transmission wave from the planar array antenna is controlled. The present invention will be described in detail below based on embodiments with reference to the accompanying drawings. FIG. 1 is a conceptual diagram showing an example of a mobile SNG system configured using the mobile SNG device of the present invention. In this example, SN
Assuming a broadcasting center 1 as a base station of the G system, a video (V) / audio (A) signal obtained by a television camera or a microphone from a moving car 2 (for example, a relay truck) or a ship 3 is transmitted to a ship. 3 is transmitted to the base station 1 via an SNG device 4 (indicated by a circle) shown as being mounted on the base station 1. OW (order wire) shown in FIG. 1 is a voice communication line between the SNG device 4 and the base station 1. Further, a pilot signal is transmitted from the base station 1 to the SNG device via the communication satellite 5.
Although the use of the pilot signal will be described later, the pilot signal is, for example, a highly stable unmodulated carrier signal transmitted using the frequency at the end of the band of the channel to be used. In the SNG device 4 shown in FIG.
A turntable on which a transmitting / receiving device and a flat array antenna are mounted is mounted on a horizontal stabilizer (which will be described later with reference to FIG. 2). Although it is kept horizontal, this horizontal stabilizer constitutes a mechanical tracking mechanism of the planar array antenna from the viewpoint of controlling the directivity of the antenna. In the electronic tracking control method, first, a pilot signal transmitted from the base station 1 via the communication satellite 5 is received by at least three sub-array antennas not arranged on the same straight line on the planar array antenna. By detecting the reception phase of each sub-array antenna, the arrival direction of the pilot signal, that is, the direction of the satellite, is detected. Based on the detection result, machine tracking in the satellite direction by the turntable (tracking in the azimuth direction) and transmission are performed. Performs electronic tracking (tracking in azimuth and elevation directions) by controlling directional characteristics. Furthermore, by detecting the polarization direction from the pilot signal received by the sub-array antenna having the polarization directions orthogonal to each other and performing the polarization control of the transmission wave, stable operation is always possible. Further, the mechanical tracking mechanism used as the coarse tracking is constituted by a turntable and a horizontal stabilizer in the SNG device 4 and is arranged on the roof of the relay vehicle 2 or on the deck of the ship 3. FIG. 2 shows the configuration of the horizontal stabilizer. As shown in FIG. 2, the turntable is arranged on a horizontal stabilizer, and the planar array antenna and the transmitting / receiving device are arranged on the turntable. As described above, the turntable performs mechanical tracking in the azimuth direction of the planar array antenna by the motor. The control (rotation control) of the turntable is performed by the output voltage of a monopulse antenna composed of a sub-array antenna in the planar array antenna. The horizontal stabilizer is a mechanical tracking mechanism that keeps the turntable horizontal even when the roof of the automobile 2 or the deck of the ship 3 is tilted in the pitch direction or the roll direction, and thus keeps the planar array antenna and the transmission / reception device at a predetermined angle. As shown in the drawing, it is composed of one fixed arm and two or more automatic telescopic arms rotatably mounted on a plurality of rotating shafts, and these telescopic arms have the same expansion and contraction in the same horizontal stabilizer. Is controlled by a gyro sensor located at Next, regarding the method of detecting the tilt angle of the polarization of the incoming wave received by the planar array antenna of the SNG device, FIG. 3 showing the configuration of the planar array antenna and FIG. 4 showing the principle of detecting the tilt angle of the polarization. This will be described with reference to FIG. In the satellite communication, the frequency differs between the uplink and the downlink, and they are orthogonally polarized to each other. Now, it is assumed that the planar array antenna constituting the mobile SNG device of the present invention is formed by arranging 5 × 5 square sub-array antennas vertically and horizontally, and the antenna configuration is shown in FIG. In FIG. 3, No. is assigned to each sub-array antenna. No. 1 to No. It is shown with serial numbers up to 25. Each sub-array antenna is composed of a plurality of antenna elements, and each antenna element can receive and transmit by itself (for both transmission and reception). For example, when the reception polarization is vertical, the transmission polarization is It is horizontal. Here, among the sub-array antennas shown by white and the four sub-array antennas shaded, 14, No. 18, No. The polarization directions of the sub-array antennas of Nos. 19 and 19 are all the same. Only the polarization directions of the 25 sub-array antennas are orthogonal to the polarization directions of the other 24 sub-array antennas (all of these directions are the same). The principle of detecting the tilt angle of the polarization (and thus the main polarization) of the incoming wave (hereinafter referred to as the main wave) from a communication satellite using the above-described planar array antenna will be described with reference to FIG. Here, among the plurality of sub-array antennas constituting the planar array antenna, only the sub-array antennas having the orthogonal polarization directions are the same. 25 and the other No. 25 polarization control sub-array antenna (indicated by N). 19 and the main polarization sub-array antenna (denoted by M). 19 has a polarization orthogonal to the polarization of the sub-array antenna No. 19 for polarization control. 25, when a pilot signal is received, 25
, The cross polarization level Er ₂ corresponding to the polarization inclination
Is received. This Er ₂ and the reception level of the main polarization Er ₁
, The inclination angle θr of the polarization of the incoming wave becomes θr = tan
^-1 (Er ₂ / Er ₁ ) (see FIG. 4). Using the detected result, as shown in FIG. 5, the polarization of the transmission wave (video (V) / audio (A) signal wave of television) which is orthogonal to the polarization direction of the reception wave. The main polarization sub-array antenna M and the polarization control sub-array antenna such that the inclination angle θt = tan ⁻¹ (Et ₂ / Et ₁ ) of the sub-array antenna becomes equal to the inclination angle θr of the detected polarization (θr = θt). N, and control the levels Et ₁ and Et ₂ of the signals input to both or one of them. With this pure electronic polarization control method, it becomes possible to perform high-accuracy and high-speed polarization tracking as compared with the mechanical tracking method of the primary feed horn performed by the conventional parabolic antenna method. The above-described polarization detection (polarization tilt angle detection) and polarization control (polarization tilt angle control) can be performed using a planar array antenna that is used for both transmission and reception. The figure is shown in FIG. Here, the planar array antenna 6
For example, No. 19 and no. 25 sub-array antennas are used for polarization detection, the polarization tilt angle θr is detected from the pilot signal received by those antennas in the polarization detection circuit 7, and based on the detection result, the N
o. The ratio of the transmission power supplied to the 25 sub-array antennas and the other sub-array antennas is controlled by the transmission polarization control circuit 8 so that the polarization inclination angle θt of the transmission wave becomes equal to the inclination angle θr. Next, a description will be given of an example of a case where the above-described mobile SNG device of the present invention is configured as an entire device by combining the respective element technologies for configuring the mobile SNG device. FIG.
Is supplied with a QPSK-modulated television video (V) / audio (A) signal and a modulated OW signal, and
A book including an information signal input / output terminal 9 from which a signal (modulated OW signal) is taken out and a control signal output terminal 10 for turning the turntable of the horizontal stabilizer (for machine tracking in the azimuthal direction of the antenna). It is a block diagram which shows an example of an inventive mobile SNG apparatus. In FIG. 7, No. is displayed at the top of the drawing. No. 1 to No. The sub-array antenna marked 25 is shown in FIG.
The antennas corresponding to the respective arrangement positions in the planar array antenna described above are shown, all of which are shared for transmission and reception. No. having the same polarization direction. 1
From No. The transmission input ports of the sub-array antennas up to 24 include a solid-state power amplifier 11, an up-converter
(L ₀ indicates a local oscillator output) and a phase shifter 13 necessary for electronically tracking the communication satellite are sequentially connected, and the input side of each phase shifter is combined into one, and QPSK is transmitted through a circulator 14. It is connected to an information signal input / output terminal 9 for signals (television signals to be transmitted to the base station) and OW signals (transmission). Also, as shown in FIG. 3, the Nos. That are not arranged on the same straight line. In addition to the above functions, the sub-array antennas 14, 18, and 19 perform reception phase detection for each sub-array antenna for electronic tracking by receiving a pilot signal, and constitute a monopulse antenna for mechanical tracking. ing. Therefore, in the overall system of the SNG device shown in FIG. 14, 18,
A low-noise amplifier 15 and a down-converter 16 are sequentially connected to the reception output port of each of the 19 sub-array antennas, and the output signal of each of the down-converters 16 is
The signals are input to a pilot signal phase detection circuit 17 and a monopulse detection circuit 18, respectively. Outputs of these circuits 17 and 18 are a CPU 19 for performing transmission beam control (phase control) for electronic tracking and a control signal output for turntable rotation. Output to terminal 10. In the CPU 19, No. 14,1
8 and 19, the direction of arrival of the pilot signal is detected from the result of the pilot signal phase detection for each sub-array antenna. No. 1 to No. The phase shifters 13 for each sub-array antenna are arranged so that the main beams of the transmission directivity characteristics of the sub-array antennas up to 24 coincide with the direction of arrival of the pilot signal.
Control. The output signal from the monopulse detection circuit 18 output to the signal output terminal 10 is input to a turntable control circuit (not shown), where a control voltage for controlling the turntable motor of the horizontal stabilizer is changed. can get. On the other hand, no. A low noise amplifier 15 and a down converter 16 are sequentially connected to the reception output ports of the 25 sub-array antennas, and the output of the down converter 16 is input to the polarization detection circuit 20. No. No. 25 in which the direction of polarization of polarization is orthogonal to the sub-array antenna of No. 25. The output of the down-converter 16 for the sub-array antenna of No. 19 is also input to the polarization detection circuit 20. It is compared with the reception level from the down converter 16 connected to the 25 sub-array antennas. Based on this comparison result, the CP
U19 detects the inclination angle of the reception polarization and transmits the polarization control circuit 2
1 to supply control information. The output of the transmission polarization control circuit 21 causes the polarization of the transmission wave to have the same inclination angle so that N
o. The transmission polarization control attenuator 22 inserted immediately before the transmission input port of each of the 25 sub-array antennas is controlled. This polarization control is performed by the control system itself shown in the conceptual diagram of FIG. 6, and the principle of the polarization detection and the polarization control has already been described with reference to FIGS. 4 and 5. Is omitted. The electronic tracking, mechanical tracking, and polarization tracking Nos. The reception ports of the sub-array antennas other than 14, 18, 19, and 25 have low noise amplifiers 1 respectively.
5 and the down-converter 16 are sequentially connected to each other, and the output signal of each down-converter 16 is supplied to an in-phase synthesizing circuit 23 for synthesizing them in the same phase, from which a received OW signal is obtained. This reception OW signal is extracted from the information signal input / output terminal 9 via the circulator 14. FIG. 8 is a block diagram showing an example of a circuit for processing signals (television signal and OW signal) supplied to and taken out from the information signal input / output terminal 9 in FIG. The signals supplied to the terminal 9 in FIG. 7 (that is, the signals output from the information signal input / output terminal 24 in FIG. 8) include a television video signal (V) and an audio signal (A). These are encoder 25, QPSK
The signal is supplied through a modulator 26 and a circulator 27 sequentially. Similarly, the signal supplied to the terminal 9 (FIG. 7) includes an OW audio signal, which is supplied sequentially through the OW modulator 28 and the circulator 27. On the other hand, the signal extracted from the terminal 9 in FIG. 7 (that is, the signal input to the terminal 24 in FIG. 8) is
This is a W audio signal, which sequentially passes through a circulator 27 and an OW demodulator 29 to operate the speaker 30 with the demodulated audio signal. The encoder 25, QPSK modulator 26, circulator 27, OW shown in FIG.
The devices other than the modulator 28, the OW demodulator 29, and the speaker 30 (ie, all the devices shown in FIG. 7) are arranged on a turntable of a horizontal stabilizer, and transfer signals to and from the devices on the turntable. The power supply to the devices on the table is configured to be performed via a rotary joint (not shown). The control signal extracted from the control signal output terminal 10 shown in FIG. 7 is a signal for controlling the rotation of the turntable in order to perform mechanical tracking in the azimuth direction of the planar array antenna. Further, the turntable must be held horizontally even when it is tilted in the pitch direction or the roll direction with the movement of the moving body. As described above, this is achieved by the horizontal stabilizer. The mobile SNG device of the present invention is not limited to the embodiment described above. For example, each sub-array antenna to be used is generally configured by a microstrip patch antenna, but may be configured by another element type such as a slot antenna. Further, in the polarization detection circuit in the above-described embodiment, No. The sub-array antenna of the other party whose level is compared with the output of the sub-array antenna of No. 25 is No. 25. No. 19 is not limited. 1
The output may be compared with the output of any of the sub-array antennas up to 24. Further, in the above-described embodiment, the turntable and the horizontal stabilizer are used as the mechanical tracking system. However, in the apparatus of the present invention, the polarization tracking is performed at high speed and with high accuracy. It is also possible to combine two-axis machine tracking systems with elevation angles. According to the mobile SNG device of the present invention, the direction (azimuth and elevation) of the communication satellite can be improved by receiving a pilot signal using a planar array antenna composed of a plurality of transmission / reception shared sub-array antennas. Since the electronic tracking and the mechanical tracking for detecting the polarization tilt angle and controlling the transmission beam based on the detection result are shared, the moving object SNG that operates at high speed and stably has been difficult to realize until now. The device can be realized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram showing an example of a mobile SNG system configured using the mobile SNG device of the present invention. FIG. 2 is a diagram showing a configuration of a horizontal stabilizer. FIG. 3 is a diagram showing a configuration of a horizontal array antenna. FIG. 4 is an explanatory diagram illustrating the principle of polarization tilt angle detection. FIG. 5 is an explanatory diagram illustrating the principle of polarization tilt angle control. FIG. 6 is a conceptual diagram showing a configuration of polarization tilt angle control. FIG. 7 is a block diagram showing an example of a mobile SNG device according to the present invention. FIG. 8 is a block diagram illustrating an example of a processing circuit for a television signal and an OW signal. [Description of Signs] 1 Broadcasting center (base station) 2 Car (mobile station) 3 Ship (mobile station) 4 SNG device 5 Communication satellite 6 Planar array antenna 7, 20 Polarization detection circuit 8, 21 Transmission polarization control circuit 9 , 24 information signal input / output terminal 10 control signal output terminal 11 solid-state power amplifier 12 up-converter 13 phase shifter 14, 27 circulator 15 low-noise amplifier 16 down-converter 17 pilot signal phase detection circuit 18 monopulse detection circuit 19 CPU 22 transmission polarization Control attenuator 23 In-phase synthesis circuit 25 Encoder 26 QPSK modulator 28 OW modulator 29 OW demodulator 30 Speaker V Video signal A Audio signal OW Order wire M Main array sub-array antenna for polarization N Sub-array antenna for polarization control

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Noboru Toyama 1-10-11 Kinuta, Setagaya-ku, Tokyo Japan Broadcasting Corporation Research Institute of Broadcasting Technology (56) References JP-A-61-16634 (JP, A) JP-A-7-142926 (JP, A) JP-A-5-281322 (JP, A) JP-A-2-32630 (JP, A) JP-A-4-61945 (JP, U) (58) Fields investigated (Int) .Cl. ⁷ , DB name) H04B ⁷ /14-7/22 H01Q 3/02 H01Q 3/34 G01S 3/42

Claims (1)

(57) [Claim 1] A plane in which a plurality of sub-array antennas shared for transmission and reception are arranged on the same plane, and the control of the directivity to the communication satellite is performed by both mechanical tracking and electronic tracking. An array antenna, the communication using a pilot signal transmitted from the base station via the communication satellite and received by at least three sub-array antennas not arranged on the same straight line among the plurality of sub-array antennas. The direction of the satellite is controlled by controlling the phase of the power supplied to the plurality of sub-array antennas based on the detection result. A mobile SNG device, wherein the polarization of one of the plurality of sub-array antennas is The direction is set to be orthogonal to the polarization direction of the other sub-array antenna, and the pilots respectively received by the one sub-array antenna and one of the other sub-array antennas By controlling the ratio of the transmission power supplied to each of the one sub-array antenna and the other sub-array antenna based on the polarization tilt angle of the arriving wave detected between the signals, from the planar array antenna A mobile SNG device characterized in that the polarization tilt angle of the transmitted wave is controlled.