JP2002043801A - Signal non-phase shift feed circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable signals to be identical in phase to each other at various receiving points, even if the signals vary in phase shift volume, depending on the transmission lines, when signals are fed from a single signal source to a plurality of receiving points through the different transmission lines. SOLUTION: Parts of the signals, received by a signal-receiving section 3 are sent back to a signal feed division 1 by the same transmission cable 2, and the phase difference between these signals and signal outputted from a signal originating device 4 is detected by a phase detector 9. A phase shift control signal, which enables the output signal of the signal originating device 4 to be shifted by a phase shifter 6 in phase by a phase volume as large as the above phase difference, is sent to the phase shifter 6 from a phase shift controller 8 by the detection signal of the phase detector 9. With this feedback system, a correction θC made by the phase shifter 6 becomes equal to the phase shift volume Δθ of the transmission cable 2, so that a phase θOUT of signals at the signal receiving section 3 becomes identical to a phase θIN of output signals of the signal originating device 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase control technique for making a phase at each receiving point in-phase when a high-frequency signal is supplied from a single source to a plurality of receiving points via a transmission line. Belongs to the field.

[0002]

2. Description of the Related Art In recent years, due to a shortage of frequency resources, communication using a relatively high frequency band, which is not always suitable for use, has become common in mobile communication due to deterioration of communication quality due to multipath. In addition, in order to increase the capacity of the communication line, by changing the transmission / reception beam shape and narrowing the beam toward the target mobile station for transmission / reception, communication with the target mobile station is performed with lower power, and In order to avoid the interference from the station, research for performing so-called adaptive antenna directivity control, which lowers the antenna directivity in the direction of the interference wave or forms null directivity, has been actively conducted. As a method of controlling the adaptive antenna directivity, an array antenna that can easily control the beam directivity by arranging a plurality of antenna elements in one or two dimensions has attracted attention.

This array antenna has a plurality of antennas.
All the antennas are used to transmit and receive signals from the element so that they are in phase in the direction in which they are to be transmitted and received, and in such a way that the signals cancel each other out in the direction of blocking transmission and reception (null direction). The phases of the elements must be well controlled and transmitted and received. Also, the amplitude affects the size of the side lobe of the transmitted and received beams, and the amplitude must also be accurately controlled for transmission and reception.

For this reason, an amplitude / phase control transmitting / receiving section (referred to as an array antenna radio section) is provided for each antenna element.
Since accurate control is not performed if there is an individual or temporal difference in phase characteristics, automatic calibration is performed (for example, Japanese Patent Application No. 11-149150, a multiple access communication device, and Japanese Patent Application No. 2000-58983). Multiple access communication device).

In this calibration method, a signal must be supplied in-phase from a signal source of a reception frequency to each array antenna radio unit, and a signal must be supplied in-phase from a signal source of a difference frequency between the transmission and reception frequencies to each array antenna radio unit. Must be supplied.

Conventionally, as means for transmitting signals supplied from a single signal source to a plurality of receiving points via separate transmission paths so that the signals have the same phase at the receiving points, a length of a transmission cable from the signal source is used. In other words, measures have been taken to make them the same and to crawl along the same path, or to measure the phase difference between each receiving point in advance and insert a phase corrector to eliminate the difference.

[0007]

However, regardless of whether the cable length is the same or the phase corrector is provided, both are fixed, so that they are subject to environmental changes, especially temperature changes and aging changes. There is a problem that even if there is a difference between the cables, it cannot be corrected.

[0008] Even if the cable lengths are the same and the cables are bundled and stretched over the same place as much as possible, there is a difference in temperature between the sunlit side and the shaded side, causing a phase difference due to the temperature difference. And the length is different,
There is a problem that a phase difference is caused by that, and also, since the degree of aging changes between the sunlit side and the non-sunlit side, or between the outside and the inside, this causes a phase difference. There is also the problem of becoming.

[0009] In addition to the above, when the cable is replaced after a predetermined period, the cable length is adjusted to the same as before, and the route and place to crawl are not different from before the replacement. However, there is also a problem that it requires attention and trouble.

In view of the above-mentioned problems of the prior art, an object of the present invention is to provide an image processing apparatus that is not affected by environmental changes and changes over time.
It is an object of the present invention to provide a signal-shiftless supply circuit in which the phase at a receiving point after passing through a transmission path becomes the same as the phase of a signal source.

[0011]

In order to achieve the above-mentioned object, a first configuration of a signal phase-shift supply circuit according to the present invention comprises a signal supply section, a transmission line, and a signal reception section. Each is characterized by having the following configuration. (1) A signal transmitter for transmitting a signal to be sent (b) A phase shifter which receives the output of the signal transmitter as an input, and shifts the phase of the signal by a phase shift control signal and outputs the phase. A circulator that sends the output of the phase shifter to the transmission line and extracts the input signal that travels backward on the same transmission line. (D) A phase that detects the phase difference angle between the reverse input signal extracted from the circulator and the transmission signal. (E) A phase shift controller that receives a phase difference angle signal from a phase detector and outputs to the phase shifter a phase control signal that causes the phase shift angle of the phase shifter to be equal to the phase difference angle. II. As a signal receiving unit (f) A circulator that receives the signal transmitted on the transmission line, sends it to the signal use circuit, and sends the branched part of the received signal back to the same transmission line again

A second configuration of the present invention uses a directional coupler in place of the circulator of the first configuration (c).

According to a third configuration of the present invention, instead of the circulator of the first configuration (f), a signal transmitted through a transmission path is sent to a signal using circuit, A transmission path impedance discontinuity point for reflecting a part of a received signal to the same transmission path is used.

A fourth configuration of the present invention comprises a signal supply unit, a reciprocating transmission line, and a signal reception unit, and each unit has the following configuration. (1) A signal transmitter for transmitting a signal to be sent. (B) A phase shifter that receives the output of the signal transmitter as input, shifts its phase by a phase shift control signal, and outputs it to the outward transmission line. (C) a phase detector for detecting a phase difference angle between the input signal from the return path and the transmission signal; and (d) receiving a phase difference angle signal from the phase detector, and detecting a phase difference angle of the phase shifter. A phase shift controller that outputs a phase shift control signal to make the angle equal to the angle to the phase shifter. II. As a signal receiving unit, (e) receives the signal transmitted on the outward transmission line and sends it to the signal use circuit. Branch circuit that sends a part of the received signal and branches it back to the return path

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention, when transmitting a transmission signal of a signal transmitter of a signal supply unit to a transmission point and transmitting the signal to a reception point of the signal reception unit, the amount of phase shift received by the transmission line is determined. By correcting the transmission signal in advance and outputting it to the transmission line, the phase at the receiving point is made to be the same as the phase at the output of the signal transmitter.

As a correction method, a part of the signal at the receiving point is returned to the signal supply unit through the same transmission path or the return transmission path if the transmission path is a reciprocal transmission path, and the phase difference between the signal and the transmission signal is detected. Then, the transmission signal is phase-corrected by the phase difference using the phase shifter, and then transmitted to the transmission line. Thus, by forming a kind of feedback system, the amount of phase shift (correction amount) by the phase shifter always matches the amount of phase shift in the transmission line, and the amount of phase shift in the transmission line changes due to environmental changes.
Even if the phase shifter changes due to a temperature change or a change over time, the phase shift amount of the phase shifter changes following the change, and the phase of the receiving point is always the same as the phase of the transmission signal.

A circulator or a directional coupler is used to send the output of the phase shifter to the transmission line and to take out the signal transmitted backward from the receiving point on the same transmission line. The means for feeding back from the receiving point may be performed by using a circulator, or may be the reflection at the impedance discontinuity point of the transmission line.

If the transmission path is a reciprocating transmission path, the signal to be sent backward from the receiving point may be sent back from the return path, and may be taken directly from the return path. There is no need to use. The present invention relates to correction control of the phase of a transmission signal, and there is no restriction on the frequency.

[0019]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a signal phase-shift supply circuit according to the present invention. FIG. 1 is a block diagram showing the configuration of a first embodiment of the signal phase-shift supply circuit of the present invention. The signal to be transmitted (transmission signal) output from the signal transmitter 4 of the signal supply unit 1 is input to the phase shifter 6 via the extraction coupler 5, and after being subjected to a phase shift of an amount described later, the circulator 7 And is output from port b and sent to transmission cable 2.

The transmission signal transmitted on the transmission cable 2 is input to the port a of the circulator 10 of the signal receiving unit 3 and output from the port b. An output signal from the port b is sent to a signal-using circuit, for example, an input terminal of an array antenna radio unit via a branch circuit 11.

In the branch circuit 11, a part of the input signal is branched and taken out, and is input to the port c of the circulator 10. The signal input to the port c is output from the port a by the function of the circulator 10 and transmitted to the transmission cable 2.
The signal is transmitted to the transmission cable 2, and is transmitted to the port b of the circulator 7 of the signal supply unit 1. The reverse signal input to port b is output to port c by the function of circulator 7. The signal output from port c is
It is input to the phase detector 9.

On the other hand, a part of the transmission signal extracted by the extraction coupler 5 is input to the phase detector 9, where
The phase difference between the transmission signal and the reverse signal that has returned to the signal receiving unit 3 is detected.

This phase difference angle signal is sent to the phase shift controller 8. Based on the phase difference angle signal, the phase shift controller 8
A phase shift control signal is sent to the phase shifter 6 so that the phase shift amount of the transmission signal in the phase shifter 6 becomes exactly the same as the phase difference angle detected by the phase detector.

By doing so, the phase shift amount of the phase shifter 6 just corrects the phase shift amount Δθ in the transmission cable 2, and the phase in the signal receiving unit 3 is The phase of the output signal (transmission signal) of the signal transmitter 4 becomes the same.

The reason is as follows. Now, the phase of the transmission signal output from the signal transmitter 4 is θ _IN , the phase shift amount in the phase shifter 6 is θ _C , the phase shift amount in the transmission cable is Δθ, and the phase of the reception signal in the signal receiving unit 3 is the theta and _OUT, the phase shift of the signal supply unit 1 and the signal receiving portion of the phase shift of the other portions in the 3 transmission cable 2 phase shift amount Δθ and the phase shifter 6 theta
It should be negligible compared to _C.

The phase θ _{IN of the} transmission signal is
In advanced by theta _C, since delayed by Δθ in the transmission cable 2, if a delay minus, take positive, Equation 1 is established between the theta _IN and theta _{OU T.}

[0027]

[Equation 1] θ _IN + θ _C -Δθ = θ _OUT

On the other hand, the phase shift amount θ _C of the phase shifter 6 is the same as the phase difference angle detected by the phase detector 9 as described above, but the phase of one input signal of the phase detector is changed. θ _IN , and the other input is a signal that has reversed, and its phase is delayed from the phase θ _OUT in the signal receiving unit 3 by the phase shift amount Δθ of the transmission cable 2, so that θ _OUT − Δθ
Next, because they later than θ _IN, from θ _IN (θ _OUT -
Δθ) is subtracted from the detected phase difference angle, that is,
will be called θ _C, equation (2) is satisfied.

[0029]

## EQU2 ## θ _C = θ _IN − (θ _OUT −Δθ)

Here, when θ _C in Expression 2 is substituted into Expression 1, Expression 3 is established, and it can be seen that the phase θ _OUT in the signal receiving unit 3 is equal to the phase θ _{IN of the} transmission signal.

[0031]

[Equation 3] θ _OUT = θ _IN

Then, when Equation 3 is substituted into the right side of Equation 2, Equation 4 is obtained, and it can be seen that the correction amount θ _C in the phase shifter 6 matches the phase shift amount Δθ in the transmission cable 2.

[0033]

Equation 4 θ _C = Δθ

As described above, since a kind of feedback system is formed in the supply circuit of the present invention, even if the phase shift amount Δθ of the transmission cable fluctuates due to environmental change or aging, the cable replacement work can be performed. Even if it fluctuates due to having been different from the previous length,
Since the phase shift amount θ _C of the phase shifter 6 follows this variation, the states of Expressions 3 and 4 can always be maintained.

As described above, when it is necessary to transmit an in-phase signal from one signal source to a plurality of locations via separate transmission paths, the phase shifter 6, the circulator 7, the phase control The object can be achieved by providing a plurality of phase shift correction circuits including the detector 8 and the phase detector 9, and also by providing a plurality of signal receiving units 3.

Further, by using one signal receiving unit as a signal source (signal transmitter 4) and configuring the circuit of FIG. 1 later, in-phase signals can be supplied to a number of receiving points in a branched manner. .

FIG. 2 is a block diagram showing the configuration of the second embodiment of the present invention. The difference from FIG. 1 is that the circulator 7 of the signal supply unit 1 of FIG. It is a point. In the directional coupler 12, the signal input from the port a is output from the port b, the signal input from the port b is output to the port c, and the circulator 7 shown in FIG.
Performs the same function as.

FIG. 3 is a block diagram showing the configuration of the third embodiment of the present invention, and the signal supply section is the same as in FIG. 1 or FIG. 2 is a transmission cable, 3 is a signal receiving unit, 31 is an impedance discontinuity point, and 32 is an impedance matching circuit. Transmission cable 2 has impedance discontinuity 3
When connected to circuits with different impedances at 1,
The signal is reflected at the impedance discontinuity point 31 and shown in FIG.
As in the case of FIG. 2, a signal for transmitting the transmission cable 2 backward is generated. Here, when the impedance at the impedance discontinuity point 31 is discontinuous to an impedance higher than the characteristic impedance of the transmission cable 2, there is no phase change of the reflected wave, and the signal is similar to the case of FIGS. A phase-shift supply circuit can be configured. On the other hand, impedance discontinuity point 3
It is known that the phase of the reflected wave changes by 180 ° at the impedance discontinuity point 31 when the impedance is converted to a value lower than the characteristic impedance of the transmission cable 2 in FIG. in this case,
The 180-degree correction may be performed by the phase shift controller 8 in the signal supply unit 1.

When the impedance is converted into an impedance having a reactance component at the impedance discontinuity point 31, the reflection phase at the impedance discontinuity point is determined by the reactance component. This phase is determined by a network analyzer or the like. The phase may be measured and corrected by the phase shift controller 8 of the signal supply unit 1, or a phase corrector (not shown) may be inserted into the signal reception unit 3.
When this phase corrector is used, if the phase is corrected so as to be the same as the input phase θ _IN of the signal receiving unit 3, a signal non-phase-shift power supply circuit can be realized as in FIGS. When the phase is corrected, the phase may be corrected by the phase shift controller 8 of the signal supply unit 1. The reason why the impedance matching circuit 32 is provided in the signal receiving unit 3 is to prevent reflection due to discontinuity of impedance at a point other than the impedance change point.

FIG. 4 is a block diagram showing the configuration of the fourth embodiment of the present invention. 1 and 2 is that the transmission cable 2 of FIGS. 1 and 2 is a single path,
In FIG. 4, the point of the reciprocating transmission cable 13 and the circulator 7 or the directional coupler 12 in the signal supply unit 1 become unnecessary, and the output of the return transmission path is directly input to the phase detector 9. Also, the circulator 10 is not required in the signal receiving unit 3 and the branched signal is connected to the return transmission line.

The operation principle of the reciprocating transmission cable 13 is the same as the operation principle in FIGS. 1 and 2 because the phase shift amount in the forward path and the phase shift amount in the return path can be regarded as the same even if there is an environmental change or a change with time. It is.

[0042]

As described above, the present invention relates to a signal supply circuit in which the amount of phase shift of a transmission line varies, sends a part of the signal received by the signal receiving section back to the signal supplying section, Since the phase difference from the output signal of the signal source is detected and the phase of the output signal is corrected by the phase difference and sent to the transmission line, the signal is received regardless of the phase shift amount of the transmission line. Section can maintain the same phase as the output phase of the signal source, and when signals are supplied from one signal source to multiple receiving points via separate transmission paths, the phase shift amount of each transmission path varies. There is an advantage that the phases of a plurality of receiving points can be the same even if they are disjointed.

As a result, as an application example, it is possible to supply an in-phase reference signal necessary for phase correction of an array antenna radio unit provided for each antenna element of an array antenna composed of a large number of antenna elements. As compared with the conventional case where there is no corrective measure in the case where the change of the outside air temperature, the change of the environment such as the temperature change due to the sunshine change or the change over time occur separately for each transmission line,
There is an advantage that antenna beam control with very little error can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of a first embodiment of a signal phase-shift supply circuit according to the present invention.

FIG. 2 is a block diagram showing a configuration of a second exemplary embodiment of the present invention.

FIG. 3 is a block diagram illustrating a configuration of a third exemplary embodiment of the present invention.

FIG. 4 is a block diagram showing a configuration of a fourth embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 signal supply unit 2 transmission cable 3 signal reception unit 4 signal transmitter 5 extraction coupler 6 phase shifter 7 circulator 8 phase shift controller 9 phase detector 10 circulator 11 branch circuit 12 directional coupler 13 reciprocal transmission cable 31 impedance non-impedance Continuous point 32 Impedance matching circuit

Claims (4)

[Claims] 1. A signal phase-shifting supply circuit comprising a signal supply unit, a transmission line, and a signal reception unit, wherein each unit has the following configuration. (1) A signal transmitter for transmitting a signal to be sent (b) A phase shifter which receives the output of the signal transmitter as an input, and shifts the phase of the signal by a phase shift control signal and outputs the phase. A circulator that sends the output of the phase shifter to the transmission line and extracts the input signal that travels backward on the same transmission line. (D) A phase that detects the phase difference angle between the reverse input signal extracted from the circulator and the transmission signal. (E) A phase shift controller that receives a phase difference angle signal from a phase detector and outputs to the phase shifter a phase control signal that causes the phase shift angle of the phase shifter to be equal to the phase difference angle. II. As a signal receiving unit (f) A circulator that receives the signal transmitted on the transmission line, sends it to the signal use circuit, and sends the branched part of the received signal back to the same transmission line again 2. A signal phase-shift supply circuit using a directional coupler in place of the circulator according to claim 1. 3. A signal transmitted through a transmission line instead of the circulator according to claim 1 is sent to a signal using circuit, and a part of the received signal is replaced with the same signal. A signal non-phase-shifting supply circuit using a transmission line impedance discontinuity point for reflection to a transmission line. 4. A signal phase-shifting supply circuit comprising a signal supply unit, a reciprocating transmission line, and a signal receiving unit, wherein each unit has the following configuration. (1) A signal transmitter for transmitting a signal to be sent. (B) A phase shifter that receives the output of the signal transmitter as input, shifts its phase by a phase shift control signal, and outputs it to the outward transmission line. (C) a phase detector for detecting a phase difference angle between the input signal from the return path and the transmission signal; and (d) receiving a phase difference angle signal from the phase detector, and detecting a phase difference angle of the phase shifter. A phase shift controller that outputs a phase shift control signal to make the angle equal to the angle to the phase shifter. II. As a signal receiving unit, (e) receives the signal transmitted on the outward transmission line and sends it to the signal use circuit. Branch circuit that sends a part of the received signal and branches it back to the return path