JPH01256201A - Transmitter-receiver having circular array antenna - Google Patents

Abstract

PURPOSE:To automatically attain the adjustment of direction by applying fix storage control to a switch stored in a memory at transmission and transmitting a signal through the opposite path to that at reception via a combiner/ distributer. CONSTITUTION:The transmitter-receiver consists of a controller 6 provided with a memory 62 applying selection control to switches S1-Sn so as to maximize a reception output of a reversible combiner/distributer 5 combining reception signals of phase shifters 21-2n and storing the position of a switch selected at its maximum value. Then the position of the switch stored in the memory 62 is subjected to fixed storage control at transmission and the signal is sent in the opposite path to that at the reception via the combiner/distributer 5. Thus, the direction is adjusted automatically at the reception.

Description

[Detailed Description of the Invention] [Summary] This invention relates to a method for automatically adjusting the pointing direction of the antenna of a single channel radio, and in particular, a transmitter/receiver having a circular array antenna that can obtain gain and phase matching over a wide frequency band. Regarding the device, the purpose is to provide a transmitting/receiving device having a circular array antenna that can automatically adjust the direction, and includes a circular array antenna that is arranged at equal intervals on the circumference and transmits and receives radio waves in a single channel method, and It is equipped with a phase shifter composed of a plurality of delay lines attached to each array antenna and a switch for selectively connecting the delay lines, and the delay line is connected to the device interval by 360'/n (n is positive). In an array antenna matching system configured with delay lines each having a path length calculated from the beam directions in integer) steps, a reversible combining/distributing device that combines the received signals of each of the phase shifters; and the combining/distributing device a controller that selects and controls the switch so that the received output of is fixedly controlled, and the configuration is such that transmission is performed via the combining/distributing device in a reverse path to that during reception.

[Industrial application field]

The present invention relates to a system for automatically adjusting the pointing direction of an antenna of a single channel radio, and more particularly to a transmitting/receiving device having a circular array antenna that can obtain gain and phase matching over a wide frequency band.

[Conventional technology]

A circular array antenna has half-wavelength doublet antennas (which may also be half-wavelength whip antennas, hereinafter simply referred to as antennas) arranged at equal intervals on the circumference, and the directivity can be adjusted to 360 degrees by changing the feeding phase of each antenna element. °
It is a well-known fact that it can be rotated, and is disclosed, for example, in Japanese Patent Application No. 59-270010 (Phase matching method for circularly arranged phased array).

FIG. 3 shows a layout diagram of a conventional circular array antenna. In the figure, n antennas (n is a positive integer)
are arranged on the circumference at equal intervals.

FIG. 4 shows a principle diagram of a conventional phase matching method for a circular array antenna. In the figure, when the two array antennas 11 and 12 are spaced apart and the beams are aligned in the θ direction (hereinafter referred to as beaming), the wavelength used to feed the antennas is λ, and the position of the antennas 11 and 12 is Since the phase difference is (2π/λ) L cosθ, it is necessary to attach a phase shifter to the antenna 11 so that the phases of the antennas 11 and 12 match in the beaming direction. At this time, if a delay line without frequency characteristics is used as a delay method for the phase shifter, and the path length A is A=LCO3θ, the phase difference obtained by this phase shifter is (2π/λ)A=(2π/λ ) L c
osθ.

Next, when the beaming direction is the same and the frequency is changed, as is clear from Figure 4, L cos θ is constant depending on the beaming direction, so even if the frequency changes, the L cos θ required to obtain the phase difference is The path length of the phase shifter is also constant. A conventional phase shifter is an application of the above basic theory to a circular array antenna.

FIG. 5 shows a block diagram of a conventional phase shifter. In the figure, the phase shifter 2 provided between the transmitter and the antenna has no frequency characteristics, and each line has a different length Al, ^2. ~An's delay line (delay line)
31.32. .about.3n, and switches Sl, S2 . . . , S2 . ~S
It is composed of n.

The switch Sl is controlled by the switch control unit 4.

S2. ~Sn is controlled to control the switching of delay lines 31, 32 . ~
By combining 3n, the beaming direction can be set, and it can be used for a wide band of frequencies.

The beaming direction setting described above is also performed for a similar phase shifter (not shown) connected to each antenna in conjunction with the control of the switch control unit 4, so that the beam direction of each antenna is aligned in a fixed direction.

In this way, each phase shifter creates the phase difference between each antenna necessary for beaming, matches the phase of each antenna in the beaming direction, and expands the emitted power by beaming at all angles (06 to 360 ”)
It can be done over a period of time.

FIG. 6 is a diagram showing an example of the directional characteristics of a circular array antenna. The value of the number n of antennas is a positive integer, and the larger the value, the higher the accuracy of beam setting.

For example, if n=3, the accuracy is too coarse in 45° increments.

If n=18, the rotation accuracy will be in 20° increments, and if n=36, the rotation accuracy will be in 10° increments.

[Problem to be solved by the invention]

In a transmitting/receiving device mounted on a flying object or a moving object, the most important problem is the antenna and the direction adjustment of the antenna. There is no particular problem if an omnidirectional antenna is used, but it is unsuitable for long-distance transmission because it has no gain.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to provide a transmitting/receiving device having a circular array antenna whose direction can be automatically adjusted.

[Means to solve the problem]

FIG. 1 is a block diagram showing the configuration of the present invention. Circular array antennas 11 to 1n arranged at equal intervals on the circumference and transmitting and receiving radio waves in a single channel system, a plurality of delay lines 31 to 3n attached to each array antenna, and the delay line. phase shifters 21 to 2n configured with switches S1 to Sn for selectively connecting the delay lines, and the delay line is arranged at an angle of 360°/n (n is a positive integer) to the arrangement interval.
In the matching method of an array antenna consisting of delay lines each having a path length calculated from the beam direction in increments,
A reversible combiner/distributor 5 combines the received signals of the phase shifters 21 to 2n, and the switches 31 to Sn are selectively controlled so that the received output of the combiner/distributor 5 reaches its maximum value. A controller 6 is provided with a memory 62 for storing the selected switch in the value, and when transmitting, it fixedly controls the switch stored in the memory 62, and through the synthesizer/distributor 5, it controls the switch in the opposite manner from when receiving. Configure the route to send.

[For production]

The received signals from each of the array antennas 11 to 1n are added with a phase difference calculated in advance by phase shifters 21 to 2n, respectively, and then input to the combiner/distributor 5.

The received signal synthesized by the synthesizer/distributor 5 is input to the receiver 8 via the transmitter/receiver switch 7 and is amplified. A part of the received signal is input to the maximum value detection section 61 that constitutes the control section 6, where a search is performed to detect the maximum value, and a search signal is sent to the switch selection section 63 at every sampling time. The switch selection unit 63 selects and controls the switches in a fixed order, and updates and stores the address of the selected switch in the memory 62. By operating the selected switch, the directivity angle of the antenna changes by 360''/n, and the level of the received signal changes in response to this change.

By performing feedback control in this manner, the directivity angle of the antenna converges to the optimum position. During transmission, the switch permanently controls the switches stored in the memory 62 until the transmission is completed. Since the transmission characteristics of the combiner/distributor 5 and the phase shifters 21 to 2n are reversible, there is no problem in transmission and reception, and automatic direction adjustment is possible at the time of reception.

〔Example〕

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

Note that, in order to make the explanation of the configuration and operation easier to understand, the same parts are given the same reference numerals throughout all the figures, and repeated explanation thereof will be omitted.

FIG. 1 is a block diagram showing the configuration of the present invention.

In the figure, antennas 11 to 1n are array antennas arranged at equal intervals on the circumference. phase shifter 21
~2n have the same configuration, and are antennas 11~1n, respectively.
It is connected to. The phase shifter 21 is connected to the delay line 31~
3n and interlocking switches 51 to Sn connected to both ends of each delay line 31 to 3n.
n is the beam direction (3
60'/n increments) and the antenna spacing. Each of the delay lines 31 to 3n and the switches 51 to Sn are arranged in order such that the beam direction is in steps of 360'/n.

Since the frequency range used covers the VHF band and the UHF band, the switches 31 to Sn are diode switches or the like that have a fast switching speed and can switch 7 to 10 circuits with one switch.

Reference numeral 5 denotes a reversible combining/distributing device which needs to have no frequency characteristics; for example, a combination of hybrid circuits or a λ/4 impedance conversion circuit may be used. It is used as a combiner during reception and as a distributor during transmission.

A DC component of the output of the receiving section 8 is sampled by a maximum value detecting section 61, and the sampled value is updated and stored in the memory 62 via the control section 6 including a CPU each time it is detected. In the initial state of reception, the control section 6 drives the switch selection section 63 to select the switches S1 to Sn in a fixed order (
(sweep)), and the switch is fixed (centered) at the position where the detection value of the maximum value detection section 61 becomes the maximum value. At this time, the beam is in an optimal state as shown in FIG. 6, matching the direction of the communication partner station. When the reception level changes during reception, it sweeps only the vicinity of the set switch within the range where the reception level does not drop, and constantly tracks the maximum reception level. Note that the transmission is switched at the switch position of the last maximum reception level stored in the memory 62.

8 and 9 indicate a receiving section and a transmitting section, respectively. This transmitting/receiving device transmits and receives radio waves of the same frequency or the frequency of the transmitting/receiving field using a single channel method, and each array antenna 1
1 to 1n are used by switching between transmission and reception using a transmitter/receiver switcher 7.

The receiving section 8 and the transmitting section 9 may be ordinary radio devices, and feedback control is performed on the maximum value detecting section 61 so that the receiving output of the receiving section 8 becomes the maximum value.

FIG. 2 shows a block diagram of a modification of the invention.

In the figure, amplifier sections 101 to 101 having the same configuration are located between each of the antennas 11 to 1n and each of the phase shifters 21 to 2n.
10n, and the amplifying section 101 is composed of a transmitting amplifying section 91, a receiving amplifying section 81, and an interlocking changeover switch Sll. The interlocking changeover switch Sll is operated by a control signal from the transmission/reception switching section 64.

As the transmission power and the like increase, the internal structure of the phase shifter becomes larger in the configuration shown in FIG. 1, resulting in higher costs. In order to improve this, the phase shifter is operated at a low level stage, and the transmission amplification section 91 attempts to obtain the required transmission power. Further, when the reception level of each antenna is too low, it is effective to use the reception amplification section 81, and when a sufficient reception level can be obtained, the reception amplification section 81 may be short-circuited.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, as a radio device for an aircraft or an automatic tracking type radio device, there is no need to adjust the direction of the antenna, and an antenna gain can be obtained regardless of the frequency.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing the configuration of the present invention, Fig. 2 is a block diagram of a modified example of the present invention, Fig. 3 is a layout diagram of a conventional circular array antenna, and Fig. 4 is a phase diagram of a conventional circular array antenna. FIG. 5 is a block diagram of a conventional phase shifter, and FIG. 6 is a diagram showing an example of the directivity characteristics of a conventional circular array antenna. 1 and 3, 5 is a combination distributor, 6 is a control unit, 62 is a memory, 11 to 1n are circular array antennas (antennas), 21 to 2n are phase shifters, 31 to 30 are delay lines, 31 ~Sn indicates a switch, and L indicates an interval.

Claims (1)

[Claims] Circular array antennas (11 to 1n) arranged at equal intervals (L) on the circumference and transmitting and receiving radio waves in a single channel system, and a plurality of circular array antennas attached to each array antenna. delay line (
31 to 3n) and a switch (S) that selectively connects the delay line.
A phase shifter (21 to 2) consisting of
n), wherein the delay line is configured with delay lines each having a path length calculated from the arrangement interval (L) and the beam direction in increments of 360°/n (n is a positive integer). In the matching method, a reversible combiner/distributor (5) combines the received signals of each of the phase shifters (21 to 2n), and the switch is configured such that the received output of the combiner/distributor (5) reaches a maximum value. (S1 to Sn) and a controller (6) equipped with a memory (62) that stores the selected switch at its maximum value, and when transmitting, the controller (6) stores the selected switch at its maximum value. 1. A transmitting/receiving device having a circular array antenna, characterized in that a switch is fixedly controlled, and transmission is performed via the combining/distributing device (5) in a reverse path to that during reception.