JP2618124B2 - Digital beam controller for transmitting array antenna. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital beam controller for a transmission array antenna applicable to a mobile satellite communication system, a land mobile communication system, or a radar antenna system.

[0002]

2. Description of the Related Art In recent years, in a mobile satellite communication system, a high-performance antenna capable of performing wide-angle and high-speed beam scanning for performing communication while tracking a satellite has been required as an antenna provided on a mobile body such as an automobile. Have been. As this kind of antenna used in the above-mentioned mobile satellite communication system, for example, a "vehicle-mounted phased array antenna for satellite communication" by Omori et al.
75, pp33-40, October 19, 1990), the on-vehicle antenna system shown in FIGS.
This is referred to as a first conventional example. ) Is disclosed.

[0003] As shown in FIG. 8, an antenna system 1 of the vehicle-mounted antenna system includes a phased array antenna 2.
, A phase shifter driving circuit 3, a diplexer 4, and a low noise amplifier 5 used in a receiving system, and these are installed on a vehicle such as a roof. Here, the antenna system 1 except for the low noise amplifier 5 is commonly used for transmission and reception. 9, the phased array antenna 2 includes 19 antenna elements 6, 18 3-bit microwave phase shifters 7, and a power distribution / synthesizer 8. The transmission-specific system that branches off from the diplexer 4 is:
Modulator 9, up-converter 10, power amplifier 11
On the other hand, the reception-specific system includes the low-noise amplifier 5, the down-converter 12, and the demodulator 13 described above. Further, the tracking system 14 includes an azimuth sensor 15 for detecting the azimuth of the vehicle, an electronic computer 16 for receiving and outputting the satellite azimuth, and an antenna for receiving the calculated satellite azimuth. And an antenna control unit 17 for transmitting the angle to the phase shifter driving circuit 3.

[0004] The operation of the vehicle-mounted antenna system configured as described above during transmission will be described below. After the transmission data signal is converted into a modulation signal of a predetermined system in modulator 9, it is converted into a signal of a predetermined transmission frequency in upconverter 10. Further, the signal is transmitted to the power amplifier 11
The signal is supplied to the phased array antenna 2 via the diplexer 4. In the phased array antenna 2, the transmission signal passing through the diplexer 4 is distributed by the power distribution / combiner 8 to each of the antenna elements 6 at a predetermined power ratio, and thereafter, the 18 signals are controlled by the tracking system 14 at regular intervals. Radiated from the antenna element 6 via the microwave phase shifter 7. Here, since the microwave phase shifter 7 common to transmission and reception is used, the beam of the transmitting and receiving array antennas can be directed substantially toward the satellite.

[0005] Further, as a circuit for forming a beam of the receiving array antenna, for example, "Digital Beam Forming Antenna by H. Steyscal";
anamingantennanas; An Int
production) (Microwave Journal International Edition, Horizon
House Microwave, Vol. 30, no. 1,
pp 107-124, January 1987).
A digital beam forming circuit (hereinafter, referred to as a second conventional example) of a zero receiving array antenna is disclosed.

The digital beam forming circuit shown in FIG.
, The antenna elements 6-1, 6-2, 6-3
, Low-noise amplifiers 51-1, 51-2, 51-3, down-converters 52-1, 52-2, 52-3, and an analog / digital conversion (hereinafter, referred to as A / D conversion) device 53-. 1, 53-2, 53-3 and a received signal reproducing circuit 6
0 and a beam control circuit 54. here,
The received signal reproducing circuit 60 includes multipliers 61-1 and 61-2,
61-3 and an adder 62.

The operation of the receiving array antenna configured as described above will be described below. Each antenna element 6-1 and 6
The signals received at -2 and 6-3 are input to down converters 52-1, 52-2 and 52-3 via low-noise amplifiers 51-1 and 51-2 and 51-3, respectively. , And then A / D-converted by A / D converters 53-1, 53-2, 53-3 to be converted into a received digital signal. The received digital signals generated corresponding to the antenna elements 6-1, 6-2, and 6-3 are input to the beam control circuit 54 and the received signal reproducing circuit 60. The beam control circuit 54 calculates, for example, a weighting factor for making all the received digital signals in-phase for each of the received digital signals, and outputs the weighted coefficients to the multipliers 61-1, 61-2, 61-3. Each of the multipliers 61-1, 61-2, and 61-3 multiplies each received digital signal by a weighting coefficient, and outputs a signal of a result of the multiplication to the adder 62. Further, the adder 62 adds all the input signals of the multiplication results, that is, power-combines the respective received digital signals in the same phase, and then outputs the combined signal as a received signal.

[0008]

As shown in the above-mentioned first conventional example, since the microwave phase shifter 7 is used for each antenna element for forming the beam of the array antenna,
There is a problem that the transmission loss of the antenna feed circuit including the insertion loss increases. In the conventional microwave phase shifter 7, the amount of phase shift cannot be set with high accuracy, so that highly accurate beam pointing in a predetermined direction and accurate pointing control such as lowering the side lobe of the beam pattern are performed. Is difficult to perform.

In order to solve these problems, a beam forming circuit for a receiving array antenna has been proposed as in the above-mentioned second conventional example, but a beam forming circuit for a transmitting array antenna is still available. Not invented.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, reduce the transmission loss of an antenna feed circuit as compared with the conventional example, and perform beam pointing control of a transmission array antenna with high accuracy. Is to provide.

[0011]

According to the present invention, there is provided a digital beam control apparatus for a transmission array antenna according to the present invention, wherein a beam control of a transmission array antenna for controlling a beam of a transmission array antenna comprising a plurality of antenna elements. A phase shift amount calculating unit (27) for calculating a phase shift amount (θ) of the transmission signal based on information on a directional direction in which the transmission signal transmitted from the transmission array antenna is to be directed; On the basis of the phase shift amount (θ) calculated by the phase amount calculating means (27), two series of baseband signals (x ₁ ,
x ₂ ), a phase shift operation of a matrix for multiplying by a phase weighting coefficient so that the transmission signal is directed in the directivity direction is performed by Equation 8
Phase shift operation means (21) for outputting two series of digital signals (y ₁ , y ₂ ) as a result of the phase shift operation after digital processing according to

(Equation 8) After performing a predetermined waveform shaping filtering process on the two series of digital signals (y ₁ , y ₂ ) output from the phase shift operation means (21), the two series of digital signals after the filtering process are performed. Waveform shaping filters (22a, 22b) that output a signal
And two series of digital carrier signals orthogonal to each other,
After performing orthogonal digital modulation in accordance with two series of digital signals output from the waveform shaping filters (22a, 22b), a modulation for outputting the modulated signal to the corresponding one of the plurality of antenna elements is performed. Means (23a, 23b, 24) and the modulated signal
It is characterized in that it is provided in front of transmission means (101-1 to 101-3, 102-1 to 102-3, 103-1 to 103-3) for performing A / A conversion, frequency conversion to a higher frequency, and amplification. And

According to a second aspect of the present invention, there is provided a transmission array antenna digital beam control apparatus for controlling a beam of a transmission array antenna comprising a plurality of antenna elements. The phase shift amount (θ) of the transmission signal is calculated based on information on the directional direction in which the transmission signal to be transmitted from the transmission array antenna should be directed, and the cosine and sine phase shift signals of the phase shift amount (θ) are calculated. A phase shift signal generating means (35) for generating (cos θ, sin θ); and a quadrature digital modulation based on the phase shift signal (cos θ, sin θ) generated by the phase shift signal generating means (35). phase Starring of the baseband signals of two series (x _1, x _2), the matrix in which the transmission signal is multiplied by the phase weighting factor to direct the directivity direction for After performing the digital processing in accordance with the number 9, the digital signals of two series of said phase shift calculation result (y _1, y ₂₎ operation means for outputting (36),

(Equation 9) After performing a predetermined waveform shaping filtering process on the two series of digital signals (y ₁ , y ₂ ) output from the arithmetic means (36), the two series of digital signals after the filtering process are output. After performing orthogonal digital modulation on two series of digital carrier signals orthogonal to each other in accordance with the two series of digital signals output from the waveform shaping filters (22a, 22b), A modulating means (23a, 23b, 24) for outputting the subsequent modulated signal to a corresponding one of the plurality of antenna elements;
Transmitting means (101-1 to 101-3, 102-1 to 1) for converting the frequency to a higher frequency and amplifying the frequency.
02-3, 103-1 to 103-3).

[0013]

[0014]

[0015]

[0016]

[0017]

In the digital beam controller for a transmission array antenna configured as described above, the phase shift operation means (21) or the operation means (36) directs a transmission signal transmitted from the transmission array antenna. Based on the phase shift amount (θ) calculated by the phase shift amount calculating means (27) based on the phase shift amount of the transmission signal for performing
The cosine and sine phase shift signals (cos θ, sin) of the phase shift amount (θ) generated by the phase shift signal generation means (35)
θ), a phase shift operation of a matrix for multiplying two orthogonal digital signals (x ₁ , x ₂ ) by a phase weighting factor so that the transmission signal is directed in the directivity direction is performed by digital. Performed by processing.

In the above digital beam control device,
Since the phase shift operation means (21) or the operation means (36) is provided, the microwave phase shifter 7 in the first conventional example is provided.
Becomes unnecessary, and the transmission loss of the antenna feed circuit corresponding to the insertion loss is reduced. Further, in the phase shift operation means (21) or the operation means (36), the phase shift operation can be performed by a digital operation with a predetermined accuracy, so that a desired phase shift accuracy can be obtained. Beam control can be performed with better directivity control than the first conventional example.

[0019]

[0020]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> FIG. 7 is a block diagram of a digital beam control apparatus for a vehicle-mounted array antenna for satellite communication according to a first embodiment of the present invention, and FIG. Transmission signal generation circuit 100 of device
It is a block diagram of. In FIG. 7, the same components as those in FIG. 10 are denoted by the same reference numerals.

The digital beam control apparatus for an array antenna according to the first embodiment, as shown in FIG.
4 generates a transmission signal for each of the antenna elements 6-1, 6-2, and 6-3 based on the elevation angle and the azimuth angle of the beam direction of the array antenna output from the antenna control unit 17 of FIG. Transmission signal generation circuit 100-1,
100-2, 100-3 (hereinafter collectively referred to as 100). In particular, in order to perform beam pointing control of the array antenna, the transmission signal generation circuit 100 includes:
As shown in FIG. 1, a phase shift operation circuit 21 for shifting the phase of a transmission signal is provided between a baseband signal generation circuit 20 and waveform shaping filters 22a and 22b.

As shown in FIG. 1, a transmission signal generation circuit 10
0 denotes a baseband signal generation circuit 20, a phase shift operation circuit 21, a phase shift amount operation circuit 27, and a waveform shaping filter 22.
a, 22b, and a quadrature modulator 30, and each circuit digitally processes each signal. Here, the orthogonal modulator 30 includes multipliers 23a and 23b, an adder 24, and an orthogonal carrier generation circuit 28. The orthogonal carrier generation circuit 28 includes a carrier generation circuit 25, a 90-degree phase shifter. 26.

The baseband signal generation circuit 20 converts the transmission data signal, which is a continuous binary data series signal,
Take any value of ± 1 to perform phase PSK modulation 2
After being converted into a series of binary pulse signals x ₁ and x _2, they are output to the phase shift operation circuit 21 at symbol timing. On the other hand, the elevation angle and the azimuth angle of the beam direction of the array antenna output from the antenna control unit 17 of the tracking system 14 are input to the phase shift amount calculation circuit 27, and the phase shift amount calculation circuit 27 Based on the angle, the transmission signal generation circuit 100
After calculating the phase shift amount θ of the signal to be transmitted from the antenna element 6 corresponding to the above, the phase shift amount is output to the phase shift operation circuit 21.

The phase shift operation circuit 21 calculates the product of a matrix expressed by the following equation ₁ with respect to the input binary pulse signals x ₁ and x ₂ based on the input phase shift amount θ. After performing a digital operation at the timing of the symbol to perform a phase shift operation of the transmission signal, a binary pulse signal y ₁ of two series of operation results is obtained.
The y _2, and outputs at the timing of the symbol waveform shaping filter 22a, to 22b.

(Equation 1)

Each of the waveform shaping filters 22a and 22b is a roll-off filter having a cutoff frequency equal to or lower than the Nyquist frequency and having a linear phase frequency characteristic.
It is composed of an R digital filter. Each of the waveform shaping filters 22a and 22b performs a predetermined waveform shaping process after sampling the input binary pulse signals y ₁ and y ₂ , and processes each digital signal after the processing at the sampling timing. And the multiplier 2 of the quadrature modulator 30
Output to 3a and 23b.

On the other hand, the carrier generation circuit 25 of the orthogonal carrier generation circuit 28 generates a digital carrier signal having a predetermined intermediate frequency, outputs the digital carrier signal to the multiplier 23a, and 90
Multiplier 23 via a 90-degree phase shifter 26 that shifts the phase by
b. Each of the multipliers 23a and 23b multiplies the two input signals, and outputs a digital signal resulting from the multiplication to the adder 24. The adder 24 receives the input 2
After the two digital signals are added, that is, the power is combined, digital-to-analog conversion (hereinafter, referred to as D / A conversion) is performed using the resulting digital signal as a transmission signal.
Output to the device 101-1, 101-2 or 101-3.
Here, the transmission signal output from the adder 24 is transmitted to the antenna element 6-1, 6-2 or 6 corresponding to the circuit 100 for beam control of the phased array antenna.
-3 has the required phase.

Further, as shown in FIG. 7, each of the transmission signals output from each of the transmission signal generation circuits 100-1, 100-2, and 100-3 is a D / A converter 101-1 and a D / A converter 101-1.
After D / A conversion in 101-2 and 101-3,
Upconverters 102-1, 102-2, 102-3
In the above, the intermediate frequency is converted into a transmission signal of a predetermined transmission frequency. The transmission signals after the frequency conversion are transmitted to power amplifiers 103-1, 103-2, 103-3.
And the diplexers 104-1, 104-2, 104-3
And antenna elements 6 juxtaposed on one straight line through
1, 6-2, and 6-3, whereby each transmission signal is transmitted from the corresponding antenna element 6-1, 6-2, or 6-3.
The beam is emitted by the tracking system 14 at the specified elevation and azimuth angles of the beam.

The antenna elements 6-1, 6-2, 6-
3 are received by the diplexer 1 respectively.
04-1, 104-2, and 104-3, the low-noise amplifiers 51-1, 5-1, 53-1 and 5-3 are used as in the second conventional example.
1-2, 51-3 and down converters 52-1, 52
−2, 52-3 and A / D converters 53-1, 53-2,
The signal is input to the beam control circuit 54 and the received signal reproduction circuit 60 via 53-3. The operation of the receiving system is the same as in the second conventional example.

In the digital beam controller for an array antenna configured as described above, the phase shift operation for controlling the transmission beam is performed by the digital operation of the phase shift operation circuit 21 in the transmission signal generation circuit 100. In addition, the microwave phase shifter 7 in the first conventional example becomes unnecessary, and the transmission loss of the antenna feed circuit corresponding to the insertion loss is reduced. Further, in the phase shift operation circuit 21, the phase shift operation can be performed by a digital operation with a predetermined accuracy, so that a desired phase shift accuracy can be obtained. Beam control can be performed with good precision pointing control. Usually, the sample rate in the waveform shaping filters 22a and 22b is
Since it is necessary to set the symbol rate to 4 times or more,
A phase shift operation with good operation efficiency can be performed.

In the above-described first embodiment, the baseband signal generation circuit 20 is replaced with each of the transmission signal generation circuits 100-1,
The present invention is not limited to this, but is provided for each of the transmission signal generation circuits 100-1 and 100-3.
One baseband signal generation circuit 20 may be provided in common for 2,100-3.

<Second Embodiment> FIG. 2 is a block diagram of a transmission signal generating circuit 100a of a digital beam control device for an array antenna according to a second embodiment of the present invention. The same components are denoted by the same reference numerals.

The transmission signal generating circuit 10 of the second embodiment
0a includes a phase shift signal generation circuit 35 and a matrix operation circuit 36 instead of the phase shift operation circuit 21 and the phase shift amount operation circuit 27, as compared with the transmission signal generation circuit 100 of the first embodiment. It is characterized by: Hereinafter, the difference will be described in detail. Note that the entire system of the digital beam control device is configured in the same manner as in FIG.

As shown in FIG. 2, the elevation angle and azimuth of the beam direction of the array antenna output from the antenna control unit 17 of the tracking system 14 are input to the phase shift signal generation circuit 35, and the phase shift signal generation circuit 35 Calculates the phase shift amount θ of the signal to be transmitted from the antenna element 6 corresponding to the transmission signal generation circuit 100a based on the input elevation angle and azimuth angle, and calculates the cosine value cos θ and the sine value of the phase shift amount θ. After calculating sin θ, a cosine value signal and a sine value signal indicating those values are output to the matrix operation circuit 36. The matrix operation circuit 36 expresses the binary pulse signals x ₁ and x ₂ input from the baseband signal generation circuit 20 based on the input cosine value signal and sine value signal by the following “Formula 2”. After performing a digital operation of the product of the matrices at the symbol timing of the binary pulse signal output from the baseband signal generation circuit 20 to perform a phase shift operation on the transmission signal, a binary pulse sequence of the operation result is obtained. The signals y ₁ and y ₂ are output to the waveform shaping filters 22a and 22b at the timing of the symbols.

(Equation 2)

The digital beam control device provided with the transmission signal generation circuit 100a configured as described above has the same functions and effects as those of the first embodiment.

In the above-described second embodiment, the baseband signal generation circuit 20 is replaced with each transmission signal generation circuit 100a-
1, 100a-2, 100a-3, but the present invention is not limited to this, and each transmission signal generation circuit 100a-
One baseband signal generation circuit 20 may be provided in common for 1, 100a-2 and 100a-3.

<Third Embodiment> FIG. 3 is a block diagram of a transmission signal generation circuit 100b of a digital beam control device for an array antenna according to a third embodiment of the present invention. The same components are denoted by the same reference numerals.

The transmission signal generating circuit 10 of the third embodiment
0b indicates that the phase shift operation circuit 21 is different from the transmission signal generation circuit 100 of the first embodiment in that the phase shift operation circuit 21 is a waveform shaping filter 22a,
It is characterized by being inserted between 22b and multipliers 23a and 23b. Hereinafter, the difference will be described in detail. Note that the entire system of the digital beam control device is configured in the same manner as in FIG.

As shown in FIG. 3, the phase shift operation circuit 21
For each digital signal z ₁ , z ₂ input from the waveform shaping filters 22 a, 22 b, a matrix expressed by the following “Equation 3” based on the phase shift θ input from the phase shift operation circuit 27. Is calculated by the waveform shaping filter 22.
After the phase shift operation of the transmission signal is performed at the sampling timing of the digital signal output from the a and 22b, the two digitals p ₁ and p ₂ of the operation result are respectively multiplied by the multiplier 23a at the sampling timing. , 2
3b.

(Equation 3)

The digital beam control device provided with the transmission signal generation circuit 100b configured as described above has the same functions and effects as those of the first embodiment.

In the above third embodiment, the baseband signal generating circuit 20 and the waveform shaping filters 22a, 22
b is used as each transmission signal generation circuit 100b-1, 100b-2,
However, the present invention is not limited to this, and each transmission signal generation circuit 100b-1, 100b-2,
One baseband signal generation circuit 20 and waveform shaping filters 22a and 22b may be provided in common for 100b-3.

<Fourth Embodiment> FIG. 4 is a block diagram of a transmission signal generating circuit 100c of a digital beam control device for an array antenna according to a fourth embodiment of the present invention. The same components are denoted by the same reference numerals.

The transmission signal generating circuit 10 of the fourth embodiment
0c is characterized in that the phase shift operation circuit 21a is inserted between the multipliers 23a and 23b and the adder 24 as compared with the transmission signal generation circuit 100 of the first embodiment. Hereinafter, the difference will be described in detail. Note that the entire system of the digital beam control device is configured in the same manner as in FIG.

As shown in FIG. 4, the phase shift operation circuit 21a
Is represented by the following “Equation 4” based on the phase shift amount θ input from the phase shift amount calculation circuit 27 for each of the digital signals q ₁ and q ₂ input from the multipliers 23 a and 23 b. The digital operation of the product of the matrices is performed by the waveform shaping filters 22a and 22a.
After the phase shift operation of the transmission signal is performed at the sampling timing of the digital signal output from b, the digital signals r ₁ and r ₂ of the operation result are respectively sent to the adder 24 at the sampling timing. Output.

(Equation 4)

The digital beam control device provided with the transmission signal generating circuit 100c configured as described above has the same functions and effects as those of the first embodiment.

In the above fourth embodiment, the baseband signal generating circuit 20, the waveform shaping filters 22a and 22
b, multipliers 23a and 23b and quadrature carrier generation circuit 28
To each of the transmission signal generation circuits 100c-1, 100c-2, 1
00c-3, but the present invention is not limited to this.
Each transmission signal generation circuit 100c-1, 100c-2, 10
One baseband signal generation circuit 20, waveform shaping filters 22a and 22b, multipliers 23a and 23b, and a quadrature carrier generation circuit 28 may be provided in common for 0c-3.

<Fifth Embodiment> FIG. 5 is a block diagram of a transmission signal generation circuit 100d of a digital beam control device for an array antenna according to a fifth embodiment of the present invention. The same components are denoted by the same reference numerals.

The transmission signal generation circuit 10 of the fifth embodiment
0d indicates that the phase shift operation circuit 21b is different from the transmission signal generation circuit 100 of the first embodiment in that the orthogonal carrier generation circuit 28
And between the multipliers 23a and 23b. Hereinafter, the difference will be described in detail.
The system of the entire digital beam controller is shown in FIG.
The configuration is the same as

As shown in FIG. 5, the phase shift operation circuit 21b
Are the carrier generation circuits 25 and 9 of the orthogonal carrier generation circuit 28.
The respective digital carrier signals s ₁ and s ₂ input from the 0-degree phase shifter 26 are expressed by the following “Equation 5” based on the phase shift θ input from the phase shift operation circuit 27. The digital operation of the product of the matrices is performed by the waveform shaping filter 22.
a, 22b after performing the phase shift operation of the transmission signal at the timing of sampling of the digital signal output from 22b, the two-series digital carrier signal t ₁ , t _{2 of the} operation result
At the sampling timing described above.
Output to 3a and 23b.

(Equation 5)

The digital beam control device provided with the transmission signal generating circuit 100d configured as described above has the same functions and effects as those of the first embodiment.

In the fifth embodiment, the baseband signal generation circuit 20, the waveform shaping filters 22a and 22
b, and the orthogonal carrier generation circuit 28 is provided for each of the transmission signal generation circuits 100d-1, 100d-2, and 100d-3. However, the present invention is not limited to this.
One baseband signal generation circuit 20, waveform shaping filters 22a and 22b, and a quadrature carrier generation circuit 28 may be provided in common for 00d-1, 100d-2, and 100d-3.

<Sixth Embodiment> FIG. 6 is a block diagram of a transmission signal generating circuit 100e of a digital beam control device for an array antenna according to a sixth embodiment of the present invention. The same components are denoted by the same reference numerals.

The transmission signal generating circuit 10 of the sixth embodiment
0e is an address generation circuit 41 instead of the phase shift operation circuit 21, the phase shift amount operation circuit 27, and the orthogonal carrier wave generation circuit 28 in comparison with the transmission signal generation circuit 100d of the fifth embodiment.
And an orthogonal carrier generation circuit 45. Hereinafter, the difference will be described in detail. Note that the entire system of the digital beam control device is configured in the same manner as in FIG.

As shown in FIG. 6, the orthogonal carrier generation circuit 4
2 stores digital carrier signal data of all phases from 0 degree to 360 degree for each predetermined phase difference, generates a corresponding digital carrier signal in response to an input address, and supplies the digital carrier signal to the multiplier 23a. A carrier memory 42 for outputting the digital carrier signal to the multiplier 23b via the 90-degree phase shifter 26 and the 90-degree phase shifter 26 are provided.

The elevation angle and the azimuth angle of the beam direction of the array antenna output from the antenna control unit 17 of the tracking system 14 are input to the address generation circuit 41, and the address generation circuit 41 performs the processing based on the input elevation angle and azimuth angle. After calculating the phase shift amount θ of the signal to be transmitted from the antenna element 6 corresponding to the transmission signal generation circuit 100e, the carrier memory stores the data of the digital carrier signal shifted by the phase shift amount θ. The address 42 is generated and output to the address terminal of the carrier memory 42. In response, the carrier memory 42 generates a digital carrier signal corresponding to the address and outputs it to the multiplier 23a,
The digital carrier signal is output to the multiplier 23b via the 90-degree phase shifter 26.

In the transmission signal generation circuit 100e configured as described above, the same operation as the phase shift operation of the phase shift operation circuit 21 of the fifth embodiment is performed in the address generation circuit 41, and the transmission signal generation circuit 100d Will work in the same way as. Therefore, the digital beam control device provided with the transmission signal generation circuit 100e has the same operation and effect as those of the fifth embodiment.

In the above sixth embodiment, the baseband signal generating circuit 20 and the waveform shaping filters 22a and 22a
2b to each transmission signal generation circuit 100e-1, 100e-
2, 100e-3, but the present invention is not limited to this, and each transmission signal generation circuit 100e-1, 100e-
2, 100e-3, one baseband signal generation circuit 20 and waveform shaping filters 22a, 22b.
May be provided.

<Other Embodiments> In each of the above embodiments,
Based on the elevation and azimuth data of the beam direction of the array antenna output from the antenna control unit 17 of the tracking system 14, each of the antenna elements 6-1 and 6-2 of the array antenna
Although the phase of the transmission signal radiated from 6-3 is controlled, the present invention is not limited to this, and may control not only the phase but also the amplitude as needed.

In each of the embodiments described above, the case of three antenna elements 6-1, 6-2, and 6-3 has been described. However, the present invention is not limited to this. The present invention can be easily applied to the case where the antenna is arranged in an arbitrary shape such as a plane shape or the like.

In each of the above embodiments, four-phase PSK modulation is used as the modulation method of the carrier signal. However, the present invention is not limited to this, and another modulation method such as 16-level QAM may be used.

In each of the above embodiments, each of the transmission signal generation circuits 100, 100a to 100e may be realized by hardware or may be realized by software of a microprocessor.

In each of the above embodiments, the transmission signal generation circuits 100 and 100 are transmitted from the antenna control unit 17 of the tracking system 14.
Although the elevation angle and the azimuth data of the beam direction of the array antenna are input to a, 100b, 100c, 100d, and 100e, the present invention is not limited to this. The phase shift amount θ or the cosine value and the sine value of the phase shift amount θ are calculated based on the data of the elevation angle and the azimuth angle.
100a, 100b, 100c, 100d, and 100e may be input.

[0063]

As described above in detail, according to the present invention, in a beam controller for a transmission array antenna for controlling a beam of a transmission array antenna composed of a plurality of antenna elements, a beam transmitted from the transmission array antenna is transmitted. (35) based on the phase shift amount (θ) calculated by the phase shift amount calculating means (27) based on the phase shift amount of the transmission signal for directing the transmission signal to be transmitted. Based on the cosine and sine phase shift signals (cos θ, sin θ) of the phase shift amount (θ) generated by the above, the transmission signal is converted into two series of digital signals (x ₁ , x ₂ ) orthogonal to each other. The phase shift operation means (21) or the operation means (3) for performing, by digital processing, a phase shift operation of a matrix for multiplying a phase weighting coefficient so as to direct in the pointing direction.
6), the microwave phase shifter 7 in the first conventional example becomes unnecessary, and the transmission loss of the antenna feed circuit corresponding to the insertion loss is reduced. Further, in the phase shift operation means (21) or the operation means (36), the phase shift operation can be performed by digital operation with a predetermined accuracy, so that a desired phase shift accuracy can be obtained. There is an advantage that beam control can be performed with better directivity control than the first conventional example. Furthermore, according to the device configuration of the present invention, the transmitting means (101-1 to 101-1) which D / A converts the modulated signal to a higher frequency and amplifies each unit of the device.
01-3, 102-1 through 102-3, and 103-1 through 103-3), the D / A converter (10
Beams of the transmission signal can be formed and controlled at a symbol rate of the transmission data signal lower than the sampling rate of 1-1 to 101-3). Therefore, a beam of a transmission signal can be formed with a smaller amount of calculation than in the second conventional example.

[Brief description of the drawings]

FIG. 1 is a block diagram of a transmission signal generation circuit of a digital beam control device for an array antenna according to a first embodiment of the present invention.

FIG. 2 is a block diagram of a transmission signal generation circuit of a digital beam control device for an array antenna according to a second embodiment of the present invention.

FIG. 3 is a block diagram of a transmission signal generation circuit of a digital beam control device for an array antenna according to a third embodiment of the present invention.

FIG. 4 is a block diagram of a transmission signal generation circuit of a digital beam control device for an array antenna according to a fourth embodiment of the present invention.

FIG. 5 is a block diagram of a transmission signal generation circuit of a digital beam control device for an array antenna according to a fifth embodiment of the present invention.

FIG. 6 is a block diagram of a transmission signal generation circuit of a digital beam control device for an array antenna according to a sixth embodiment of the present invention.

FIG. 7 is a block diagram of a digital beam control device for an array antenna used in each embodiment according to the present invention.

FIG. 8 is a block diagram showing a first conventional example of a vehicle-mounted phased array antenna system for satellite communication.

FIG. 9 is a block diagram of the phased array antenna of FIG.

FIG. 10 is a block diagram of a beam control circuit of a second conventional receiving array antenna.

[Explanation of symbols]

 6, 6-1, 6-2, 6-3: antenna element, 20: baseband signal generation circuit, 21: phase shift operation circuit, 22a, 22b: waveform shaping filter, 23a, 23b: multiplier, 24: addition 25, a carrier generation circuit, 26, a 90-degree phase shifter, 27, a phase shift amount calculation circuit, 28, a quadrature carrier generation circuit, 30, a quadrature modulator, 35, a phase shift signal generation circuit, 36, a matrix calculation 41, an address generation circuit, 42, a carrier wave memory, 45, a quadrature carrier generation circuit, 100, 100a to 100e, a transmission signal generation circuit, 101, a D / A converter, 102, an up converter, and 103, a power amplifier.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location H04L 27/36 H04L 27/00 F (72) Inventor Kiyohiko Uehara Kyoto, Soraku-gun, Soraku-gun, Kyoto 5 Mihiratani, ATR Optical Co., Ltd. (72) Inventor Masayuki Fujise Kyoto, Soraku-gun, Seika-cho, Daiya, Inaya, 5th Mihiratani Co., Ltd., ATR Optical Co., Ltd. (56 References JP-A-59-50603 (JP, A) JP-A-3-119844 (JP, A) JP-A-60-149203 (JP, A) JP-A-63-46026 (JP, A)

Claims (2)

(57) [Claims] 1. A beam control device for a transmission array antenna for controlling a beam of a transmission array antenna including a plurality of antenna elements, based on information on a directional direction in which a transmission signal transmitted from the transmission array antenna should be directed. The phase shift amount calculating means (27) for calculating the phase shift amount (θ) of the transmission signal, and the phase shift amount (θ) calculated based on the phase shift amount (θ) calculated by the phase shift amount calculating means (27). The phase shift operation of a matrix for multiplying _two baseband signals (x ₁ , x ₂ ) for orthogonal digital modulation by a phase weighting factor so that the transmission signal is directed in the directivity direction is performed by several steps. After performing the digital processing according to the above-mentioned (6), a phase shift operation means (21) for outputting two series of digital signals (y ₁ , y ₂ ) as a result of the above phase shift operation; After performing a predetermined waveform shaping filtering process on the two series of digital signals (y ₁ , y ₂ ) output from the phase shift operation means (21), the two series of digital signals after the filtering process are performed. Waveform shaping filters (22a, 22b) that output a signal
The two digital carrier signals orthogonal to each other are output from the waveform shaping filters (22a, 22b).
Modulating means (23a, 23b, 24) for performing quadrature digital modulation according to a series of digital signals and outputting the modulated signal to the corresponding one of the plurality of antenna elements; To D / A
Transmitting means (101-1 to 101-3, 102-1 to 1) for converting the frequency to a higher frequency and amplifying the frequency.
02-3, 103-1 to 103-3), a digital beam control device for a transmission array antenna, characterized in that it is provided in the preceding stage. 2. A beam control device for a transmission array antenna for controlling a beam of a transmission array antenna including a plurality of antenna elements, based on information on a directional direction in which a transmission signal transmitted from the transmission array antenna should be directed. A phase shift signal generating means (35) for calculating a phase shift amount (θ) of the transmission signal and generating cosine and sine phase shift signals (cos θ, sin θ) of the phase shift amount (θ); Based on the phase-shifted signal (cos θ, sin θ) generated by the phase-shifted signal generating means (35), the input two-series baseband signals (x ₁ , x ₂ ) for quadrature digital modulation are input. After digitally performing a phase shift operation of a matrix for multiplying by a phase weighting coefficient so that the transmission signal is directed in the directivity direction according to Equation 7, two series of digital data of the phase shift operation result are obtained. A signal (y _1, y ₂₎ operation means for outputting (36), ## EQU7 ## After performing a predetermined waveform shaping filtering process on the two series of digital signals (y ₁ , y ₂ ) output from the arithmetic means (36), the two series of digital signals after the filtering process are output. Waveform shaping filters (22a, 22b) and two sets of digital carrier signals orthogonal to each other are output from the waveform shaping filters (22a, 22b).
Modulating means (23a, 23b, 24) for performing quadrature digital modulation according to a series of digital signals and outputting the modulated signal to the corresponding one of the plurality of antenna elements; To D / A
Transmitting means (101-1 to 101-3, 102-1 to 1) for converting the frequency to a higher frequency and amplifying the frequency.
02-3, 103-1 to 103-3), a digital beam control device for a transmission array antenna, characterized in that it is provided in the preceding stage.