JPH0229005A - Beam shaping device for antenna - Google Patents

Abstract

PURPOSE:To reduce components of a module and the quantity of beam shaping operation by providing an analog phase shifter, using a power combiner so as to shape a linear beam, decreasing number of signals and applying A/D conversion so as to apply digital beam shaping calculation. CONSTITUTION:A output signal of a power combiner 3 is mixed with a local oscillation signal by a mixer 14 via a filter 13 in an A/D conversion module and becomes an intermediate frequency signal. Then the signal is converted into a digital signal by an A/D converter 16 via a filter and the result is fed to a beam shaping operation circuit 5. Let longitudinal and lateral component number be Ny, Nx, then complex number multiplications of Nx.Mx times are required to shape Mx lines of beam in the lateral direction in the said antenna. In the case of comparing number of times of the complex number operations of a beam shaping circuit of a conventional system with that of this system, 122880 times of the operations are required for the conventional system in comparison with 1920 times in this invention and then the operation quantity is reduced considerably.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a beam forming device for a phased array antenna.

[Conventional technology]

FIG. 7 is a configuration diagram of a conventional antenna that performs digital beam forming. In the figure, 1 is an element antenna, and 6 is a D
B F (Digital Beam Formin
g) Module 5 is a beamforming calculation circuit that performs digital calculations for beamforming.

FIG. 8 is a diagram showing the configuration of the DBF module 6. In the figure, 11 is a low noise amplifier, 13 is a filter, 14 is a mixer, 15 is a filter, and 16 is an A/D converter.

Next, the operation will be explained. The high frequency signal received by the element antenna l is sent to the low noise amplifier 1 in the DBF module 6.
1, passes through a filter 13, and is mixed with a local oscillation signal at a mixer 14 to become an intermediate frequency signal. The intermediate frequency received signal passes through a filter 15, is converted into a digital signal by an A/D converter 16, and is sent to a beam forming calculation circuit 5.

Now, assuming that the number of antenna elements (the number of element antennas 1 and DBF modules 6) is lateral force direction N x s and vertical direction Ny, and the output signal of each module 6 is s (kx, ky), the beam forming calculation is as follows. The following DFT (discrete Fourier transform) is obtained.

Ny With this antenna, a total of Mx in the horizontal direction and My in the vertical direction
To form XMy beams, Nx-Ny-M
x-My complex multiplications are required.

[Problem to be solved by the invention]

Since the conventional antenna beam forming device is configured as described above, a filter 13 is provided for each DBF module.
, a mixer 14, a filter 15, and an A/D converter 16, which increases the circuit scale and requires a large amount of calculation for beam formation. There were problems such as the need for a large-scale beamforming calculation circuit.

This invention was made to solve the above-mentioned problems, and when either or both of the number of formed beams MX and My in the horizontal and vertical directions is 1, a small and inexpensive device can be constructed. The purpose of the present invention is to obtain a beam forming device for an antenna that can perform the following steps.

[Means to solve the problem]

The antenna beam forming device according to the present invention includes an analog phase shifter, performs one-dimensional beam forming using a power combiner, reduces the number of signals, and then performs A/D conversion.
It is designed to perform digital beam forming calculations.

[Effect]

In this invention, the beam forming device of the antenna is provided with an analog beam forming circuit in the A/D converter of the received signal, so the amount of beam forming calculations is small (and the number of components is reduced). , the digital beamforming calculation circuit becomes small and inexpensive.

〔Example〕

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

FIG. 1 shows an antenna beam forming device according to an embodiment of the present invention, in which 1 is an element antenna, 2 is a receiving module, 3 is a power combiner (power combining means), and 4 is an A
The /D conversion module 5 is a beamforming calculation circuit (beamforming processing means) that performs digital calculations for beamforming.

FIG. 2 is a diagram showing the configuration of the receiving module 2. In the figure, 11 is a low noise amplifier, and 12 is a phase shifter (phase shifting means).

FIG. 3 is a diagram showing the configuration of the A/D conversion module 4, in which 13 is a filter, 14 is a mixer, 15 is a filter,
16 is an A/D converter.

Next, the operation will be explained. The high frequency signal received by the element antenna 1 is transmitted to the low noise amplifier 1 in the receiving module 2.
After being amplified by a phase shifter 12 and given a desired amount of phase shift necessary for vertical beam formation, a power combiner 3 forms a vertical beam.

By setting the ny-th phase shift amount φny of all Ny elements in the vertical direction, the output of the power combiner 3, S, becomes θ
A beam can be formed in the direction.

Note that s (ny) is the output signal of the ny-th receiving module.

The output signal of the power combiner 3 passes through the filter 13 in the A/D conversion module, is mixed with the local oscillator signal in the mixer 14, becomes an intermediate frequency signal, and passes through the filter to the A/D converter 16.
The signal is converted into a digital signal and sent to the beam forming calculation circuit 5.

Now, the number of horizontal elements (the number of A/D conversion modules 4) is N
x and the output signal of each module is s (kx), the beam forming operation is the following DFT.

In order to form Mx beams in the horizontal direction (one beam in the vertical direction) with this antenna, Nx-Mx complex multiplications are required. Here, Nx=64. N)'=64. Mx=3
0. For the case of (My-1), when comparing the number of complex operations with the beam forming circuit of the conventional method, it is 122.880 times for the conventional method and 1.920 times for the method of this embodiment, which can significantly reduce the amount of calculations. .

In the above embodiment, the case where Mx beams are formed in the horizontal direction is explained, but when forming My beams in the vertical direction, the same effect can be obtained by providing a power combiner in the horizontal direction. play.

Furthermore, when constructing a monopulse antenna, it can be constructed by dividing the power combiner into two as shown in FIG. In FIG. 4, 1 is an element antenna, 2 is a receiving module, 3 is a power combiner, 4 is an A/D conversion module, and 5 is a beam forming calculation circuit.

Further, when the antenna is an active phased array antenna that is used for both transmission and reception, the effect of the present invention is even greater because the phase shifter and power combiner can be used also as the phase shifter and power divider for transmission. The operation in this case will be explained with reference to FIGS. 5 and 6.

FIG. 5 is a configuration diagram of a transmitting/receiving antenna according to an embodiment of the present invention. In the figure, 1 is an element antenna, 7 is a transmitting/receiving module, 3 is a power combiner, 8 is a transmitting/receiving switch, 4 5 is an A/D conversion module, 5 is a beam forming calculation circuit, and 9 is a power divider.

FIG. 6 is a diagram showing the configuration of the transmitting/receiving module 7 of FIG.
2 is a phase shifter.

The transmission signal is distributed to each element array by a power divider 9, passes through a transmission/reception switch, and is distributed to each transmission/reception module 7 by a power combiner 3. Phase shifter 12 in the transmitter/receiver module 7
The phase shifter is controlled so as to form a desired beam, the beam is amplified by the power amplifier 18 via the transmitter/receiver switch 17a, and is radiated into space from the element antenna 1 via the transmitter/receiver switch 17b. In the case of reception, the explanation is the same as above except that the signal passes through the transmitter/receiver switchers 17a, 17b and the low noise amplifier 11.

〔Effect of the invention〕

As described above, according to the antenna beam forming device according to the present invention, since the analog beam forming circuit is provided before A/D conversion of the received signal, the number of component parts of the module can be reduced ( Since the amount of calculation is reduced, the beam forming calculation circuit can be made smaller and cheaper.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an antenna beam forming device according to an embodiment of the present invention, FIG. 2 is a block diagram of a receiving module according to an embodiment of the present invention, and FIG. A configuration diagram of a D conversion module, FIG. 4 is a configuration diagram of a monopulse antenna showing another embodiment of the present invention,
FIG. 5 is a block diagram of an active phased array antenna to which another embodiment of the present invention is applied, FIG. 6 is a block diagram of a transmitting/receiving module in another embodiment of the present invention, and FIG. 7 is a block diagram of a conventional digital beam forming antenna. Configuration diagram, No. 8
The figure is a configuration diagram of a conventional DBF module. In the figure, 1 is an element antenna, 2 is a receiving module,
3 is a power combiner, 4 is an A/D conversion module, 5 is a beam forming operation circuit, 6 is a DBF module, 7 is a transmitting/receiving module, 8 is a transmitting/receiving switch, 9 is a power divider, 11 is a low noise amplifier, 12 13 is a phase shifter, 13 is a filter, 14 is a mixer, 15 is a filter, 16 is an A/D converter, 17 is a transmission/reception switch, and 18 is a power amplifier. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) A beam forming device for a phased array antenna includes a plurality of analog phase shift means for shifting the received signals of the element antennas arranged in an array by a required amount, and outputs of the phase shift means for each row or column. A plurality of power combining means that respectively combine power; and an A/D that demodulates and A/D converts the output of the power combining means.
1. A beam forming device for an antenna, comprising: a converting means; and a beam forming calculating means for performing a digital beam forming calculation on the output of the A/D converting means to form a beam in a column or row direction.