JPH0530143Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial field of application] This invention combines the rotational output of a bidirectional antenna (hereinafter referred to as bidirectional antenna output) and the output of an omnidirectional antenna (hereinafter referred to as sense antenna output). Measurement of the direction of arrival of radio waves (hereinafter referred to as direction measurement) using a unidirectional rotational output obtained by combining the The present invention relates to a wireless direction finder (hereinafter referred to as direction finding) that selects and determines one direction (hereinafter referred to as sense determination).

[Conventional technology]

In this type of direction finding, the sense antenna output is set at 90°.
By varying the phase shift constant depending on the frequency of the radio wave used for direction measurement, by inverting the relative phase with the bidirectional antenna output for sense inversion, and by changing the magnitude of the sense antenna output. It is necessary to adjust the size to match the multidirectional antenna output.

A technology that mechanically performs this selection in conjunction with a receiving frequency band selector switch, a tuning dial knob, etc. (hereinafter referred to as the first conventional technology)
is well known, and in order to eliminate such switching operations, amplifier circuits are interposed in the sense antenna signal input circuit and the bidirectional antenna signal input circuit, respectively, and a reactance and a reactance are provided on the output side of each amplifier circuit. By obtaining the sense antenna reception signal and the bidirectional reception signal from each voltage division point of the series circuit with the resistor, the total phase shift value of each series circuit can be used to obtain both signals, regardless of the reception frequency. A technology that allows the phase difference between received signals to be kept constant at 90 degrees (hereinafter referred to as the second conventional technology) was published in Japanese Patent Application Laid-Open No. 1983-
17381 and others.

In addition, in a matching circuit between a transmitting circuit and an antenna, there is a technology (hereinafter referred to as the third conventional technology) that enables automatic matching by selectively connecting reactance elements suitable for the transmitting frequency using the signal representing the frequency channel itself. It is disclosed in Japanese Patent Application Laid-open No. 54-153507 and others.

[The problem that the idea attempts to solve]

The above-mentioned second conventional technique eliminates wear-out failures caused by mechanical components as in the first conventional technique, but requires a phase-shifting amplifier circuit on both the sense antenna receiving signal side and the bidirectional receiving signal side. In addition, the amplification degree of both amplification elements must be the same, and the amount of phase shift changes as the amplification element changes over time.Furthermore, due to the characteristics of the active amplification element, the required There is also a limit to the frequency range in which the amount of phase shift can be maintained, and this results in inconveniences such as inability to apply especially when direction finding over a wide frequency range is required.

For this reason, even if the signal representing the frequency channel in the third prior art described above is configured to select a reactance or a phase shift constant appropriate to the frequency, as described above, even if the signal represents a frequency channel, In the case of direction finding, there remain disadvantages such as the need to set and memorize all frequencies to be used within a wide frequency range.

For this reason, there is a problem in that it is desired to provide a device with a simple and inexpensive configuration that does not have these inconveniences.

[Means to solve the problem]

In order to measure the direction of arrival of radio waves over a wide frequency range using the bidirectional antenna output and the sense antenna output as described above, this invention uses a plurality of phase shift constants to shift the phase of the sense antenna output. In a radio direction finder having a function of selecting from among phase constants, the above-mentioned wide receiving frequency range is divided into a plurality of regions, and a dividing frequency means sets a frequency value corresponding to the boundary of each region as each dividing frequency; a region signal means for obtaining a signal corresponding to one of the regions as a region signal based on a signal obtained by comparing the frequency of the sense antenna with the respective partition frequencies; region-compatible phase shift constant means for setting a plurality of phase shift constants corresponding to each of the regions, and selecting a predetermined one of the phase shift constants based on the region signal. The above-mentioned problem can be solved by providing a phase shift constant selection means for obtaining a signal obtained as a sense phase shift signal.

〔Example〕

Examples will be described below with reference to figures.

First, the overall configuration will be described. In FIG. 1, a multidirectional antenna 1 is, for example, a loop antenna, and outputs an output obtained by rotating the directional direction as a directional antenna output signal 1a.

The omnidirectional antenna 2 is, for example, a vertical antenna, and outputs the received wave output as an omnidirectional antenna output signal 2a.
Output as .

The phase shift circuit 3 is provided with a plurality of phase shift circuits in which the values of the resistor R, capacitor C, inverting transformer T, etc. are varied, as shown in FIG. 6, for example. Select the one that suits the purpose of the omnidirectional antenna output signal 2a.
The phase of the directional antenna output signal 1a is shifted (theoretically by 90 degrees), and a signal matched with the phase of the directional antenna output signal 1a is output as a phase-shifted signal 3a.

The sense operation circuit 4 is, for example, a relay circuit, and is activated when necessary to provide the phase-shifted signal 3a to the synthesis circuit 5. The operating circuit 4 is excluded and the phase-shifted signal 3a is sent to the combining circuit 5.
is entered directly into

The combining circuit 5 applies a phase-shifted signal 3a to, for example, an intermediate tap of a high-frequency input transformer of the receiving circuit 6, and mixes the directional antenna output signal 1a and the phase-shifted signal 3a and outputs the mixture as a combined signal 5a. .

The receiving circuit 6 is, for example, a synthesizer-type receiving circuit, and receives and amplifies the composite signal 5a and outputs it as a receiving circuit 6a.

The direction detection circuit 7 is a combination of a gate circuit, a counter circuit, a comparison circuit, etc., and receives the received signal 6a.
The azimuth component is detected, and the azimuth value is output as a digital signal, with a sense determination signal attached if necessary, as an azimuth signal 7a.

The display circuit 8 is a display circuit using, for example, an LED or a cathode ray tube, and visually displays the azimuth value using a character image, direction pointing image, or the like.

The frequency circuit 9 is, for example, a register circuit,
A signal representing the frequency being received by the receiving circuit 6 is converted into a digital value signal and outputted as a frequency signal 9a.

As will be described later with reference to FIGS. 3 to 5, the comparison circuit 10 is a combination of a digital switch group including a plurality of digital switches capable of setting arbitrary digital values, and a plurality of comparison circuits and AND circuits. A plurality of preset digital values and the value of the frequency signal 9a are compared, and the frequency signal 9 is placed in any of the areas defined by the plurality of digital values.
Compare the signal detected to see if there is a value of a and use the detection signal 1
Output as 0a.

The selection circuit 11 is, for example, a plurality of relays,
Activate the relay corresponding to the comparison detection signal 10a, select one of the objectives in the phase shift circuit 3,
A selection path 11a is formed to be connected to the line of the omnidirectional antenna output signal 2a. Next, a specific example of the main part will be explained. In FIG. 2, the positive/inverse phase circuit 300 is the inverting transformer T shown in FIG. 300a・Reverse phase signal 300
b.

The phase shift constant circuits 301(1) to 300(n) are a group of phase shift constant circuits in which the values of R and C shown in FIG. ~
302(n)a, and outputs a phase-shifted signal 3a from each output point.

The relay circuit 303 is a one-pole, two-throw type relay circuit, and is controlled by an inversion control signal 305a.
Either one of the positive phase signal 300a and the negative phase signal 300b is selected as the sense signal 303a, and 180° phase shift (phase inversion) is selected. Relay circuit 302(1)
~302(n) is a one-pole, one-throw relay circuit,
The desired one of them is controlled by the selection control signals 304(1)a to 304(n)a, and the line of the sense signal 303a is connected to the selection sense signal 302(1)a.
-302(n)a is selected as one or more of the lines.

Buffer circuits 304(1) to 304(n), 305 are buffer amplification circuits such as operational amplifier circuits, and select signals 307(1)a to 307(n)a and inverted signals 30
6a is amplified to a signal suitable for relay control, thereby preventing interference of each signal due to each relay operation. This circuit can be excluded if the relay circuits 302(1) to 302(n), 303 and the AND circuits 307(1) to 307(n) are unlikely to interfere. The switch circuits 306(1) to 306(n) are 1-pole, 1-throw type manual setting switches, and the selection signals 307(1)a to 307(n)a correspond to those set in advance. is selected as the inverted signal 306a.

AND circuits 307(1) to 307(n) are AND gate circuits, which take the logical sum of the outputs of a plurality of comparison circuits (to be described later) given as input, so that the value B of the frequency signal 9a falls within a specified range. The AND circuit 307(1) will be described later with reference to FIG. 5 as a representative example.

The set switches 309(0) to 309(n) are each a switch group consisting of a plurality of single-pole, single-throw type manual setting switches, and apply power V ₁ according to the setting method of each switch. The set switch 309 outputs a multi-digit digital value signal as a range value signal _A0 to _Ao .
(0) and 309(1) will be described later with reference to FIG. 5 as a representative example.

Comparison circuits 308(0) to 308(n) are comparator circuits that compare two given values, compare and detect the magnitude of the other value with respect to that one value, and output the result, for example, as shown in FIG. An integrated circuit consisting of a group of gate circuits such as the one shown in FIG. 4 outputs a comparison detection signal by a combination of terminals configured as shown in FIG. This will be described later with reference to FIG. Then, the set switches 309(0) to 309(n) are manually set to each frequency value of the change point that requires various changes in the phase shift constant of the sense antenna output depending on the frequency of the radio wave, according to the actual measurement value at the site. Set and range value signal
Frequency signal 9 for area values partitioned by A ₀ ~ A _o
Regarding the value of frequency value signal B of a, the area to which it applies is defined as Range value signal A ₀ < Frequency value signal B Range value signal
A ₁ Range value signal A ₁ < Frequency value signal B Range value signal
Comparison circuits 308 (0) to 308 (n), as in A ₂ range value signal A _o-1 <frequency value signal B range value signal A _o ,
Selected by AND circuits 307(1) to 307(n),
Ultimately, the desired purpose can be selected from among the relay circuit 303 and phase shift constant circuits 301(1) to 301(n) of the phase shift circuit 3.

Hereinafter, a typical example of the main part will be explained with reference to FIG. Set switch 309(0), 309(1)
By manually closing each switch in the switch groups S ₀₁ to S ₀₃ and S ₁₁ to _{S 13} , the range value signals A ₀ and A ₁ of the frequency value to be set are converted to a decimal number by the digital value of the BCD code. Numerical value of each 3-digit digit A ₀₁ ~
Set A ₀₃ , A ₁₁ to A ₁₃ .

Frequency value signal B is a 3-digit decimal value of each digit B ₀₁ ~
It is divided into digital values of the BCD code of _B03 and applied to integrated circuit blocks IC-1 to IC-3 and IC-11 to IC-13 constituting comparison circuits 308(0) and 308(1). These integrated circuits are those of FIG.

AND the output of range value signal A ₀ <frequency value signal B of integrated circuit blocks IC-1 to IC-3 and the output of range value signal A ₁ frequency value signal B of integrated circuit blocks IC-11 to IC-13. The circuit 307(1) gates and outputs a signal in which range value signal A ₀ <frequency value signal B range value signal A ₁ is detected as a selection signal 307(1)a.

The switch circuits 306(1) and 306(2) are each 1
It is formed using switches S ₀₁ and A ₁₁ , which have a larger number of switches by an order of magnitude. In the figure, H and L indicate high and low level power supplies.

Note that this invention can be implemented in the following modifications.

(1) Compare circuit 3 with AND circuits 307(1) to 307(n)
08(0) to 308(n).

(2) Relay circuits 302(1) to 302(n), 303 are configured with electronic relay circuits such as diode gate circuits.

(3) Comparative detection of frequency ranges such as range value signal A ₀ < frequency value signal B range value signal A ₁ and how to take upper and lower limit values such as range value signal A ₀ frequency signal B < range value signal A ₁ change.

(4) Set the frequency signal 9a as the local oscillation frequency and set the range value signals A ₀ to A _o to values corresponding to this, or
Or set switches 309(0) to 309
A circuit that adds or subtracts the intermediate frequency is added to (n) to convert it into a corresponding value and output it.

(5) To the sense antenna output phase shift circuit 3 in the case of multi-directional antenna output, which outputs a signal obtained by cross-switching each antenna pair without rotating the multi-directional antenna output for direction measurement. The configuration is the same for both.

[Effect of idea]

According to this invention, as mentioned above, the selection of the phase shift constant in a wide reception frequency range is as simple as setting the frequency value corresponding to the boundary of each area where the wide reception frequency range is partitioned into multiple areas. In addition to simple operations, it is very simple to select a predetermined phase shift constant based on the signal for each area, that is, the area signal obtained based on the signal that compares the received frequency and the set frequency value. Because of this configuration, the device has the advantage of being able to be provided at a low cost.

[Brief explanation of the drawing]

The drawings show an embodiment, and FIG. 1 is a schematic diagram of the overall block configuration, FIG. 2 is a block diagram of the main parts, and FIG.
6 to 6 are configuration diagrams of main circuits. 1... Multidirectional antenna, 2... Omnidirectional antenna, 3... Phase shift circuit, 4... Sense operation circuit,
5... Synthesis circuit, 6... Receiving circuit, 9... Frequency circuit, 10... Comparison circuit, 11... Selection circuit, 3
08(0)-308(n)... Comparison circuit, 309
(0) to 309(n)...Set switch (digital value setting).

Claims (1)

[Claims for Utility Model Registration] 1. In order to measure the direction of arrival of radio waves over a wide frequency range using a multi-directional antenna output and a sense antenna output, a plurality of phase shift constants for shifting the phase of the sense antenna output are used. A radio direction finder (hereinafter referred to as a device) having a function of selecting from among phase shift constants, a) dividing the wide receiving frequency range into multiple regions, and using a frequency value corresponding to the boundary of each region as each partition frequency; b. area signal means for obtaining a signal corresponding to one of the areas as an area signal based on a signal obtained by comparing the received frequency with each of the partition frequencies; , c. region-based phase shift constant means for setting the plurality of phase shift constants to which the sense antenna output is applied to each phase shift constant corresponding to each region, and d. and phase shift constant selection means for selecting a predetermined one of them and obtaining a signal obtained as a phase shift signal for sensing. 2. The device according to claim 1 of the utility model registration claim, comprising: a) the partition frequency means for setting each of the frequency values by each digital switch; and b) the digital value of the received frequency and each of the digital switches. c. the area signal means for obtaining the area signal by logically ORing a plurality of comparison outputs obtained by comparing each digital signal set to , by each comparison circuit, with an AND circuit; c. the phase shift constant selection means for supplying the phase shift constant to each of the phase shift constants via each relay circuit, and operating a predetermined one of the relay circuits by the area signal to obtain the phase shift signal; A device characterized by: