JPH02151104A - Antenna system - Google Patents

Abstract

PURPOSE:To improve the S/N of communication by providing a phase shifter for correcting a phase correcting a phase change attended with a plane changeover of a phased array antenna for each phased array so as to decrease the phase change attended with the lane changeover of the phased array antenna. CONSTITUTION:A phased array A is in use initially. Then when the beam scanning direction is changed and enters the beam scanning region using a phased array B, a switch 4 is changed over to connect the phased array B and a receiver 5. A correction phase arithmetic unit 7 calculates a phase quantity phi, and a corrected phase -phi and a correction phase shifter controller 8 generates a control signal to allow a correction phase shifter PB sets a phase -phi. Then correction phase shifters PA, PB, PC, PD and PE correct a phase change by the plane changeover. Thus, the phase change attended with the plane changeover of the phased array antenna is reduced, the S/M of the communication is improved and the communication with high accuracy is attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an antenna device, and particularly relates to an antenna device that transmits a signal to a position jF1.
The present invention relates to a phased array antenna used for modulated communication.

[Conventional technology]

Figure 3 shows, for example, an electronics conference recorder (Electro, Conf, Rec, 1
984 Fil)'l.

1.1 to 4.1.3) are diagrams showing the configuration of the conventional antenna device shown in FIG. 3 fa) is a top view, and FIG.
bl is a front view. In the figure, A, B, C, D, and E are phased array antennas. FIG. 4 is a diagram showing the configuration of a phased array antenna. In the figure, 1 is an element antenna, 2 is a phase shifter, and 3 is a combiner. FIG. 5 is a diagram showing the connection state of the phased array antennas A, B, C, D, and E. In the figure, 4 is a switch and 5 is a receiver.

Next, the operation will be explained.

In one phased array antenna, the phase shifter 2 shown in FIG. 4 changes the phase of the radio wave signal received by the element antenna 1 to scan the beam.

If high gain is required over half the space, phased arrays A, B, and C are used, as shown in FIG.

D and E are arranged in a polygonal manner, and the beam scanning range of each phased array is shown in FIG. 4 at an opening angle θ. be within the cone of 1
The beam scanning range of the phased array on the surface is θ. If the number exceeds 1, the switch shown in FIG. 5 is changed and beam scanning is performed using another phased array.

[Problem to be solved by the invention]

The conventional antenna device was configured as described above.
Next, consider the case where this antenna device is used for communication. When phase modulation is used as the modulation method, communication information is transmitted by modulating and demodulating the phase of the composite signal. Therefore, when the direction of arrival of the signal changes and beam scanning is performed, it is necessary to keep the gain high and to keep the phase of the composite signal constant. For example, in a spread spectrum method that performs phase modulation, the phase change is generally lO.

Above this, the signal-to-noise ratio of communication deteriorates, and the modulation locks off at 30 degrees or above. FIG. 6 shows phase changes when a digital phase shifter is used in an 80-element phased array. As shown in Fig. 6, when a 3-bit phase shifter is used, if the setting error is 17.5° (r, m, s) or more,
The phase change will be 10" or more. With a normal phase shifter, the setting error is considered to be about 10' (r, m, s), so
In beam scanning of a one-plane phased array, the phase change is considered to be small. However, when using multiple phased arrays by switching as shown in Figure 5,
A phase change occurs depending on the distance between the phase centers of the array.

Generally, the distance between these phase centers is larger than the wavelength, and therefore the phase change is also large enough to not be ignored.

Therefore, there was a problem that the signal-to-noise ratio was poor.

This invention was made to solve the above-mentioned problems, and its purpose is to provide an antenna device that can reduce the phase change caused by switching the plane of a phased array antenna and improve the signal-to-noise ratio of communication. do.

[Means to solve the problem]

The antenna device according to the present invention is provided with a phase shifter for phase correction that corrects a phase change caused by switching the plane of the phased array antenna for each phased array.

[Effect]

The antenna device according to the present invention has a configuration in which each phased array is provided with a phase shifter for correcting the phase that occurs when changing the plane of the phased array antenna. Changes can be reduced and the signal-to-noise ratio of communications can be improved.

〔Example〕

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

FIG. 1 is a diagram showing the configuration of an antenna device according to an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 5 indicate the same or corresponding parts, PA, PB.

PC, PD, and PE are correction phase shifters connected to the next stage of the synthesizer of each phased array, and 6 is the correction phase shifter PA.
, PB, PC, PD, and PE, and 7 is a correction phase calculation device.

Next, the operation will be explained.

Assume that phased array A is used in the initial state. Here, if the beam scanning direction changes and enters the beam scanning area where phased array B is used, the first
Switch 4 shown in the figure is switched to connect phased array B and receiver 5. Here, the unit vector in the beam scanning direction for switching from phased array A to phased array B is dl, the position vector of the phase center of phased array A is lrg, and the position vector of the phase center of phased array B is lrB. The phase change φ when switching from phased array A to phased array B is expressed by the following equation.

(λ is the wavelength) The correction phase calculation device 7 calculates the phase amount φ and the correction phase −φ by the calculation of equation (1), and the correction phase shifter control device 6 generates a control signal to set the phase of the FIG. 2 is a flowchart illustrating the above procedure.

In this way, in this embodiment, the correction phase shifter PA.

Since phase changes due to plane switching are corrected by PB, PC, PD, and PE, highly accurate communication is possible by using a phased array that switches planes for a communication system that performs phase modulation.

〔Effect of the invention〕

As described above, in the antenna device according to the present invention, since the phase shifter for correcting the phase is provided for each phased array to correct the phase change caused by the surface switching of the phased array antenna, the phase shifter is provided for each phased array. The phase change caused by switching the plane of the antenna can be reduced, the quantity ratio of the communication signal pair 91 can be improved, and this has the effect of enabling highly accurate communication.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the configuration of an antenna device according to an embodiment of the present invention, FIG. 2 is a flowchart diagram showing the control operation of the present invention, FIG. 3 is a diagram showing the configuration of a conventional antenna device, and FIG. 4 is a diagram showing the configuration of a phased array antenna,
FIG. 5 is a diagram showing the connection state of the phased array antenna, and FIG. 6 is a diagram showing the relationship between the setting error of the phase shifter and the amount of phase fluctuation. 1 is an element antenna, 2 is a phase shifter, 3 is a combiner, 4 is a switch, 5 is a receiver, 6 is a correction phase shifter control device, 7 is a correction phase calculation device, A, B, C, D. E is a phased array antenna, PA, PB, PC, P
D and PE are correction phase shifters. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] (1) having a plurality of phased array antennas each having a plurality of element antennas, a phase shifter connected to each of the element antennas, and a combiner that combines the outputs of the phase shifters;
In an antenna device that uses a switch to switch between the phased array antennas, a correction phase shifter is provided between the combiner of each of the phased array antennas and the switch, and a combined received electric field accompanying switching of the phased array antennas is provided. a correction phase calculation device that calculates a phase change of the correction phase shifter and calculates a set phase amount of the correction phase shifter for correcting the phase change; An antenna device comprising: a correction phase shifter control device for controlling a phase shifter.