JP2629219B2 - Diversity receiver for satellite broadcasting - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in the following order.

A Industrial Fields B Outline of the Invention C Prior Art D Problems to be Solved by the Invention E Means for Solving Problems (FIG. 1) F Function G Embodiment G ₁ Circuit Configuration (FIG. 1) To FIG. 4) G ₂ circuit operation (FIG. 5) H Effect of the invention A Industrial application field The present invention is suitable for use in receiving satellite broadcasts on a moving body such as a ship or an automobile. The present invention relates to a diversity receiver for satellite broadcasting.

B. SUMMARY OF THE INVENTION The present invention provides a plurality of phased array antennas arranged in different directions, compares the output levels of the plurality of phased array antennas, selects the maximum level antenna output, and selects the maximum level By electrically controlling the azimuth and elevation angle so that the output of the antenna is optimal, the response time is fast to the movement of the moving body and it can always follow the radio wave in 360 ° direction It is like that.

C Prior Art In general, there is a diversity reception system as a method of improving or reducing the quality of a reception wave by compensating or reducing fading in a short-wave band. Can be considered. In other words, when a microwave antenna is mounted on a moving object, the direction of the antenna changes according to the movement of the moving object, the reception sensitivity changes, and a state like a kind of fading is exhibited, so it is necessary to deal with this. It is conceivable to use a diversity reception method. Therefore, as a diversity reception method of an antenna for microwaves, a method of mechanically moving a combination of a plurality of antennas has been conventionally proposed. Also,
One of the electronic scanning antennas is a so-called phased array antenna, which achieves a desired excitation phase of each element by controlling a transfer device.

D Problems to be Solved by the Invention By the way, in the case of the method of mechanically moving as described above, there is a problem that the response time is slow with respect to the movement of the moving body. Further, since only one phased array antenna is conventionally used, there is a problem that a range in which a beam can be moved, that is, a range in which an incoming radio wave is followed is narrow.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and provides a diversity receiver for satellite broadcasting that has a quick response time to the movement of a moving body and can always immediately follow a 360-degree radio wave. To provide.

E Means for Solving the Problems The diversity receiver for satellite broadcasting according to the present invention can electronically control a beam, a plurality of phased array antennas (1 to 4) arranged in different directions, and a video signal And a peak level detecting means for sequentially detecting the output levels of the plurality of phased array antennas during the vertical blanking period, and selecting the maximum level antenna output by comparing the output levels detected by the peak level detecting means. Maximum level selecting means (10), storage means (10) for storing control information of the phased array antenna selected by the maximum level selecting means, and the storage means each time the selected phased array antenna moves. The phase of the selected phased array antenna is controlled by the control information from the Phase control means for electrically controlling the azimuth and elevation so that Le (32), those having a.

F function A plurality of phased array antennas (1 to 4), that is, a plurality of microwave antennas capable of electronically controlling a beam are arranged in different directions, that is, in all directions. During the vertical blanking of the video signal, the peak level detector (13) sequentially detects the output levels of the plurality of phased array antennas (1 to 4), and outputs the detected output levels to a microcomputer (hereinafter referred to as a microcomputer). In step (10), the antenna output of the maximum level is selected. The microcomputer (10) generates a control signal for the selected antenna and controls the phase control circuit (32) of the phased array antennas (1 to 4) to optimize the output of the antenna (maximum level). Azimuth and elevation are electrically adjusted as described above. As a result, the response time becomes faster with respect to the movement of the moving body, and it is possible to immediately follow radio waves in all directions.

G. Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5, taking an example in which the present apparatus is mounted on a moving body.

G ₁ circuit configuration Figure 1 is shows an embodiment of the invention. In the figure, (1) to (4) is a phased array antenna, first second attached to the phased array antenna
This will be described with reference to FIGS.

FIG. 2 shows a circuit configuration in which a plurality of circularly polarized radiating elements are co-phase-fed by a suspended line, thereby forming an array. The solid line in FIG. 3 shows a state cut along the line II in FIG. 2, and the broken line in FIG. 3 shows a state in which the second metal plate covers the state in FIG. Is shown.

2 and 3, (21) is a first metal plate (or metallized plastic plate) as a lower plate, (22) is a second metal plate (or metallized plastic plate) as an upper plate, (23) is a thin film substrate (film-like flexible substrate) sandwiched between the first and second metal plates (21) and (22). The first metal plate (21) has a projection (2) for holding the substrate (23).
4), the second metal plate (22) has a hole having a diameter of, for example, 14 mm, a so-called slot-shaped hole (25) and a convex-shaped hole provided near the hole for holding the substrate (23). Protrusion (26)
(Fig. 3). First and second metal plates (21),
When holding the substrate (23) at (22), use the protrusions (24) and (2)
6) Positioned to match. At this time, the thicknesses of the first metal plate (21) and the second metal plate (22) are extremely thin, for example, about 1 mm each. When the substrate (23) is sandwiched between the first and second metal plates (21) and (22), a cavity (27) passing through the hole (25) is formed.

(28) is the hole (25) of the second metal plate (22) in the substrate (23)
A so-called patch-shaped surface-resonant printed element (radiating element) concentrically attached to the hole (25) corresponding to the hole (25), and the radiating element (28) is provided with a hollow portion (27). And a suspended line (feeding line) (29).
In this case, the radiating element (28) having a substantially circular shape has a diameter that resonates at a predetermined frequency, and has a predetermined angle, for example, 45 degrees with respect to the suspended line in order to receive or transmit circularly polarized waves.
An opposing notch is provided at the position ゜.

Here, as described above, the first metal plate (21) is provided with the projection (24) for holding the substrate (23) so as to avoid the radiating element (28) and the suspended line (29). A projection (24) is also provided on the outer periphery of the array. Other parts constitute the cavity (27). As a result, a plurality of suspended lines (29) may pass through the same hollow portion (27), and there is a fear of mutual coupling.
By properly selecting the distance between the suspended lines (29) and the distance between the upper and lower walls of the cavity (27), the required isolation can be obtained without any problem. At this time, the lines of electric force are concentrated on the upper and lower walls of the cavity (27), so that there is almost no electric field along the supporting substrate (23), thereby reducing the dielectric loss and consequently the line. Transmission loss will be reduced.

Also, a projection and a cavity are formed on the second metal plate (22) corresponding to the first metal plate (21). That is, the radiating element (28) and the suspended line (29) are held in the vicinity of the hole (25) formed in the second metal plate (22) and in the periphery of the array so as to hold the substrate (23). Protrusion (26)
Are provided, and the other portions are hollow portions (27) (see FIG. 3).

Since the substrate (23) is uniformly held by the projections (24) and (26) provided in this manner, the substrate (23) does not sag, and the surroundings of each radiating element and the feeder are the same as the conventional case. Since the plates (21) and (22) are in close contact with each other, no resonance or the like occurs at a specific frequency.

In Figure 2, divided into four groups G ₁ ~G ₄ four sixteen radiating elements (28) as a set. Connection point P ₁ of each group lambda] g / 2 from the center (lambda] g is the line wavelength at the center frequency) offset, connection points P ₂ and P ₃ are connected lambda] g / 4 staggered with. Thus, in each group, the lower right radiating element (28) is 90 °, the lower left radiating element (28) is 180 ° and the upper left radiating element (2
8) are 270 ° out of phase with each other, thereby improving the axial ratio. That is, the axial ratio is broadened by changing the spatial phase and the feed line phase.

The connection point P ₁ and P ₄ to P ₆ for each group feeding unit (3
They are interconnected so as to be equidistant from the feed point (31) of (0). In such a configuration, the connection points P ₁ and P ₄ ~
It is possible to obtain various directivity characteristics by changing the position of the P ₆ changing the feeding phase and the power distribution ratio. That is, the phase is changed by changing the distance from the feed point (31) to the connection point P ₁ and P ₄ to P _6, also, or thin lines where branches of the suspended line (29), Alternatively, the amplitude is changed by changing the impedance ratio by increasing the thickness, so that the directional characteristics can be arbitrarily changed.

Thus, in this embodiment, a planar array antenna as shown in FIGS. 2 and 3 is used as a phased array antenna. The details of this planar antenna are described in
See 263157.

Now, in this embodiment, as shown in FIG.
A phased array antenna is constructed by inserting a phase control circuit (32) all around 8). This phase control circuit (3
For example, 2) is used as shown in FIG. That is, in FIG. 4, the phase control circuit (32) has a variable capacitance element (32a) connected between the suspended line (29) and the ground, and its voltage is controlled by a control signal from the microcomputer (10) (FIG. 1). DC power supply (32
b), a coil (32c) connected to the DC power supply (32b) and the cathode side of the variable capacitance element (32a), and the coil (32c).
c) and a capacitor (32d) connected between the connection point of the DC power supply (32) and ground. The coil (32c) and the capacitor (32d) constitute a signal blocking circuit for preventing a signal from the suspended line (29) from flowing into the DC power supply (32b).

Returning to FIG. 1, the description will be continued. (5) to (8) are feed points (3) of the phased array antennas (1) to (4), respectively.
The BS converters connected to 1), these BS converters (5) to (8) convert the frequency of the received radio wave to a predetermined frequency. For example, BS converters (5) to (8)
Converts 12GHz radio waves to 1GHz radio waves. The output sides of the BS converters (5) to (8) are connected to the contacts a to d of the switch circuit (9), respectively. The switching circuit (9) is switched by a switching signal from the microcomputer (10) as described later. The memory of the microcomputer (10) (not shown)
The control for instructing the voltage supplied from the DC power supply (32b) to the variable capacitance element (32a) of the phase control circuit (32) in accordance with the azimuth and the elevation angle in relation to the phased array antennas (1) to (4) Information is stored in advance.

The output signals (BS-IF signals) of the BS converters (5) to (8) are selected by a switch circuit (9) and output from a BS tuner (1).
Supplied to 1). The BS tuner (11) selects a desired channel from the BS-IF signals, and demodulates a television video signal and an audio signal from the FM signal. This demodulated output is supplied to the television receiver (12) and displayed.

Further, the video signal from the BS tuner (11) is supplied to the microcomputer (10), and the microcomputer (10) switches the contacts a to d of the switch circuit (9) during the vertical blanking period of the video signal.
Switch. During this vertical blanking period, the outputs of the phased array antennas (1) to (4),
The demodulated output of the BS tuner (11) is the peak level detector (1
3) and the peak level is detected. The peak level detected for each antenna is calculated by microcomputer (10)
The antenna output of the maximum level is selected and compared, and the control information of the corresponding antenna, that is, the DC power supply (32b) is supplied to the variable capacitance element (32a) of the phase control circuit (32) of the selected antenna at that time. ) Is stored in the memory of the microcomputer (10). Each time the mobile body moves, the phase of the selected antenna is controlled by the control information from the microcomputer (10), and the azimuth and elevation of the maximum level are set.

G ₂ Circuit Operation Next, the circuit operation of FIG. 1 will be described with reference to FIG. In step (b), the operation starts, and in step (b), the microcomputer (10) looks at the video signal from the BS tuner (11) to determine whether or not it is a vertical blanking period. It waits until a blanking period, and when it is a vertical blanking period, supplies a switching signal to the switch circuit (9) to sequentially switch its contacts a to d, and outputs the outputs of the phased array antennas (1) to (4) to BS respectively. It is supplied to the BS tuner (11) via the converters (5) to (8).
Then, in step (c), a peak level detector (13) to which the demodulated output of the BS tuner (11) is supplied detects a peak level for each antenna and supplies the detected peak level to the microcomputer (10).
The microcomputer (10) compares the supplied peak levels and selects the maximum level antenna output. Then, control information corresponding to the voltage supplied from the DC power supply (32b) to the variable capacitance element (32a) of the phase control circuit (32) of the selected antenna is stored in the memory of the microcomputer (10).

However, considering that the present apparatus is mounted on a moving body, the direction of the antenna should change according to the movement of the moving body. Accordingly, the output of the selected maximum level antenna also changes in accordance with the movement of the moving object, so that it is necessary to adjust the azimuth and the elevation angle so that the antenna becomes more optimal (maximum level).

Therefore, in step (d), the microcomputer (10) supplies the control information to the phase control circuit (32) of the selected antenna to perform the phase control, and sets the azimuth angle to the maximum level.

The memory of the microcomputer (10) has the variable capacitance element (32a) of the phase comparison circuit (32) according to the azimuth and elevation as described above.
Since the control information indicating the voltage supplied from the DC power supply (32b) is stored in advance, the control information before and after the azimuth at which the maximum level antenna output was obtained as described above is read and subjected to phase control. That is, the beam of the antenna is swung right and left.

For example, assuming that the azimuth when the maximum level of antenna output is obtained is 10 ° at the upper right in the drawing of FIG. 2, the radiating element (28) in the leftmost column is 0 °, and the second 10 ° for the radiating element (28) in the row, 20 ° for the radiating element (28) in the third row from the left, and 20 ° in the radiating element (28) in the fourth row from the left (ie, the rightmost row). The control information is set in the memory of the microcomputer (10) so as to apply a voltage from the DC power supply (32b) to the variable capacitance element (32a) so that a delay of 30 ° occurs. By increasing the delay amount of the radiating element closer to the arriving radio wave in this way, the currents from the respective radiating elements as viewed at the feeding point (31) are in phase, and the current can be efficiently fed.

Then, the control information of the azimuth before and after this azimuth of 10 °, for example, 9 ° or 11 ° is read out from the memory of the microcomputer (10), and the antenna beam is substantially shaken and observed. For example, when the azimuth is 9 °, the radiating element (28) in the leftmost column is 0 °, and the radiating element (28) in the second column from the left is 9 °.
゜, 18 ゜ for the radiating element (28) in the third row from the left, 27 に は for the radiating element (28) in the fourth row (ie, the rightmost row) from the left, and 11 ゜Sometimes the radiating element (28) in the leftmost column is 0 °, the radiating element (28) in the second column from the left is 11 °, and the radiating element (2
The variable capacitance element (32a) is configured such that a delay of 22 ° occurs in 8) and a delay of 33 ° occurs in the radiating element (28) in the fourth column from the left.
The control information from the memory of the microcomputer (10) is applied to the DC power supply (32b) so as to apply a voltage to the DC power supply (32b). Of course, at this time, the elevation angle is set to a certain value.

The demodulated output level from the BS tuner (11) at each azimuth is detected by the peak level detector (13), and the control information at the maximum level is stored in the memory of the microcomputer (10) and Set.

Next, in step (e), the control information is sent from the microcomputer (10) to the phase control circuit (32) of the selected antenna.
To control the phase, and set the elevation angle to the maximum level.

That is, in this case as well, with the azimuth angle fixed at a certain value, for example, with the azimuth angle obtained at the maximum level fixed before and after the elevation angle at which the maximum antenna output was obtained as described above. Is read and the phase is controlled. That is, the beam of the antenna is swung right and left.

For example, if the elevation angle when the maximum level antenna output is obtained is 35 ° when viewed from above and below the drawing in FIG. 2,
0 ° for the radiating element (28) in the top row, 35 ° for the radiating element (28) in the second row from the top, 70 ° for the radiating element (28) in the third row from the top, The radiating element (28) in the fourth row from the upper side (that is, the lowermost row) receives a variable capacitance element (32) from the DC power supply (32b) so that a delay of 105 ° occurs.
Control information is set in the memory of the microcomputer (10) to apply a voltage to a).

Then, the control information of the elevation angle before and after the elevation angle of 35 °, for example, 34 ° or 36 ° is read from the memory of the microcomputer (10), and the antenna beam is substantially shaken and observed. For example, when the elevation angle is 34 °, 0 is set for the radiating element (28) in the uppermost row.
゜, the radiating element (28) in the second row from the top is 34 上 側, the radiating element (28) in the third row from the top is 68 ゜, and the fourth row from the top (ie, the bottom row) ) Radiating element (28)
At an elevation angle of 36 °, the uppermost radiating element (28) at 0 °, and the radiating element at the second row from the upper side (2
8) is 36 °, radiating element (28) in the third row from the top is 72 °, and radiating element (28) in the fourth row from the top is 108
The control information from the memory of the microcomputer (10) is supplied to the DC power supply (32b) so as to apply a voltage to the variable capacitance element (32a) so that the delay occurs in each of (4).

Then, the demodulated output level from the BS tuner (11) at each elevation angle is detected by the peak level detector (13), and the control information at the maximum level is stored in the memory of the microcomputer (10) to set the elevation angle. I do.

In this way, the azimuth and the elevation of the maximum level are set, and when the mobile body moves again, the above operation is repeated.

In this embodiment, the azimuth can be adjusted within a range of ± 45 ° for each antenna.
It can be adjusted in the range of 30 ゜ to 46 ゜.

In the above embodiment, the phase control circuit (32) connection point P ₁ for each group as shown by the broken line in Figure 2
May be inserted near to control the phase roughly.

H Effect of the Invention As described above, according to the present invention, the output of the maximum level antenna is selected by comparing the output levels of a plurality of phased array antennas, and the orientation is selected so that the output of the maximum level antenna is optimal. Since the angle and the elevation angle are electrically controlled, the response time to the movement of the moving object is fast, and the radio wave in the 360 ° direction can always be followed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a power supply circuit diagram of a main part of the present invention, and FIG. 3 is a line II in FIG.
, FIG. 4 is a block diagram of a main part of the present invention, and FIG. 5 is a flowchart for explaining the operation of the present invention. (1) to (4) are phased array antennas, (5) to
(8) is BS converter, (9) is switch circuit, (10)
Is a microcomputer, (11) is a BS tuner, (13)
Is a peak level detector, and (32) is a phase control circuit.

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-203403 (JP, A) JP-A-58-12440 (JP, A) Jikai Sho 61-103906 (JP, U) 20922 (JP, B2)

Claims (1)

(57) [Claims] 1. A plurality of phased array antennas capable of electronically controlling a beam and arranged in different directions, and a peak level for sequentially detecting output levels of the plurality of phased array antennas during a vertical blanking period of a video signal. Detection means; maximum level selection means for comparing the output level detected by the peak level detection means to select the maximum level antenna output; and storing control information of the phased array antenna selected by the maximum level selection means. Each time the selected phased array antenna moves, the phase is controlled by the control information from the storage means, and the azimuth and elevation are adjusted so that the output of the selected phased array antenna is at the maximum level. And phase control means for controlling electrically. Diversity receiving device for satellite broadcasting.