JP2003304136A - Infinite phase unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compact and low cost infinite phase unit whose phase variation value can be extended to 360° in a simple configuration using a reflex phase shifter. <P>SOLUTION: An infinite phase unit is configured by combining the reflex phase shifter 25 and a 90° discrete phase unit 22 and a decoder 26. The 90° discrete phase unit 22 is configured of a phase distributor 23 for distributing the phase of a signal to be inputted from an input terminal 21 to 0°, 90°, 180°, and 270° and a switch part 24 for selecting the output of a phase distributor 23 according to a phase control signal 27. Also, the decoder 26 controls a switch part 24 of the 90° discrete phase unit 22 and the reflex phase shifter 25 based on the phase control signal 27. The reflex phase shifter 25 performs phase variation under control shown by a figure 7 to the signal outputted by the switch part 24 of the 90° discrete phase unit 22, and outputs it from an output terminal 28. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase shifter for arbitrarily controlling the phase of various signals in a wireless communication device or other electronic equipment, and in particular, it uses a reflective phase shifter having a phase variable amount of about 90 °. It realizes an infinite phase shifter extended to a phase variable amount of 360 °.

[0002]

2. Description of the Related Art FIG. 7 is a block diagram showing a configuration example of a conventional reflection type phase shifter. This reflection type phase shifter comprises an RF input terminal 1, a 90 ° hybrid circuit 2, varactor diodes 3A and 3B, a phase control terminal 4, an RF output terminal 5 and the like. The input is divided into two by the 90 ° hybrid circuit 2, the reflection angle of the signal distributed in the hybrid circuit 2 is controlled by the two varactor diodes 3A, 3B, and the phase of the RF output at the RF output terminal 5 is changed. Is. The varactor diodes 3A and 3B are elements that change their capacitances by the bias voltage from the phase control terminal 4, and by this capacitance variation, the reflection angle of the input of the varactor diodes 3A and 3B is controlled, and the 90 ° hybrid circuit 2 again controls them. The RF output terminal 5 is synthesized and the phase is changed at the RF output terminal 5.

The phase variable amount of such a reflection type phase shifter is
Determined by the capacitance change ratio of the varactor diodes 3A, 3B,
In a general varactor diode, the variable capacitance value is several pF.
~ Several tens pF, capacitance change ratio is several tens pF / several pF (= 2
0), and the amount of phase change is as small as about 90 °. Therefore, conventionally, the following method has been proposed in order to expand the phase variable amount to 360 ° and realize an infinite phase shifter.

(First Conventional Example) FIG. 8 is a block diagram showing the configuration of an infinite phase shifter constructed according to the first conventional example. This infinite phase shifter includes four reflection type phase shifters 12-1,
12-2, 12-3, and 12-4 are connected in series between the input terminal 11 and the output terminal 13, and the phase variable range is 90 ° ×.
4, which is an extension of 360 °. The phase of each reflection type phase shifter 12-1, 12-2, 12-3, 12-4 is controlled by the phase φ control signal 14, and the phase variable range is controlled to 0 ° to 360 °. (Second conventional example; Japanese Patent Laid-Open No. 10-294763) This second conventional example expands the phase variable amount of the reflective phase shifter by combining a four-phase phase modulator and a reflective phase shifter. Yes, the phase is 45 ° by the 4-phase modulator,
135 °, 225 °, 315 °, that is, 45 ° × n
After being discretely varied to (n = 1, 2, 3, 4), the reflection type phase shifter is continuously varied by 90 ° to expand the amount of phase variation.

[0005]

However, when four reflection type phase shifters are connected in series as in the above-mentioned first conventional example, the gain variation when the phase is changed, the variation of the phase f characteristic and the like are also four. However, there is a drawback that the characteristics are deteriorated. For example, a typical reflection type phase shifter has a relative bandwidth of 5%
And, the gain fluctuation is about 1 dBpp, and the phase f characteristic fluctuation is 1 °.
It is about pp, and when 4 units are connected in series, it is 4 because of gain fluctuation.
The phase f characteristic is deteriorated to about 4 ° pp with a fluctuation of about dB pp.
Further, there are disadvantages that the use of four reflection type phase shifters causes an increase in circuit scale and an increase in cost.

When the four-phase modulator is used as in the second conventional example, two ring modulators, a 90 ° phase modulator, a power combining circuit, a ring modulator control circuit, etc. are required. Therefore, there is a drawback that the circuit configuration becomes large-scaled and the cost becomes high. In addition to the above, a plurality of 90 ° hybrid circuits and a variable attenuator are combined to form a discrete phase shifter (Japanese Patent Laid-Open No. 2001-136043), and an infinite phase shifter using two balanced modulators. Structure (Japanese Patent Laid-Open No. 58-847336, Japanese Patent Laid-Open No. 2001-184888)
No.) is known, but it is difficult to provide an infinite phase shifter which is small in size and low in cost because of its complicated structure.

Therefore, an object of the present invention is to provide a small-sized, low-cost infinite phase shifter having a simple structure using a reflection type phase shifter and capable of expanding the amount of phase shift to 360 °.

[0008]

In order to achieve the above-mentioned object, the present invention has a phase distributor that distributes an input signal discretely for each phase difference of about 90 ° and a 90 ° discrete phaser. A reflection type shifter for inputting a signal selected by the switch unit of the 90 ° discrete phase shifter and a 90 ° discrete phase shifter having a switch unit for selecting a signal and performing a 90 ° continuous phase change on the signal. And a phaser.

In the infinite phase shifter of the present invention, the input signal is discretely split by the phase splitter for each phase difference of about 90 °,
An arbitrary phase signal from 0 ° to 360 ° can be obtained by selecting one of them by the switch unit and performing 90 ° continuous phase variation on the selected signal by the reflection type phase shifter. Therefore, since the phase variable amount can be expanded to 360 ° by the 90 ° discrete phase shifter capable of a simple configuration and the single reflection type phase shifter having the phase variable amount of about 90 °, the circuit configuration is simple and high. Performance, small size,
Infinite phase shifter can be realized at low cost.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of an infinite phase shifter according to the present invention will be described below. In the present embodiment, an infinite phase shifter having a phase shift amount of 360 ° is realized by using a reflection type phase shifter having a phase shift amount of about 90 °, and an input signal is converted by using a hybrid circuit or a transmission line. 0
90 ° discrete phase shifter which discretely distributes to 90 °, 90 °, 180 ° and 270 ° and selects the distributed signal with a switch according to the phase control amount, and a reflection type shifter capable of 90 ° continuous phase variable. It is a combination of a phaser.

FIG. 1 is a block diagram showing a configuration example of an infinite phase shifter according to an embodiment of the present invention. This infinite phase shifter includes a reflection type phase shifter 25 using a varactor diode described in the conventional example, a 90 ° discrete phase shifter 22 and a decoder 26.
Is a combination of. The 90 ° discrete phase shifter 22 is
The phase of the signal input from the input terminal 21 is 0 °, 90 °
A phase divider 23 for dividing into 180 °, 180 ° and 270 °,
A switch unit 24 (switches 0 to 3) that selects the output of the phase distributor 23 according to the phase control signal 27. Further, the decoder 26 controls the switch unit 24 of the 90 ° discrete phase shifter 22 and the reflection type phase shifter 25 based on the phase control signal 27. The reflection type phase shifter 25 has 9
The phase of the signal output from the switch unit 24 of the 0 ° discrete phase shifter 22 is changed by the control shown in FIG. 7 and output from the output terminal 28.

Next, the operation of the infinite phase shifter of this example will be described. First, the phase control signal 27 is transmitted through the decoder 26 in the form of (90 ° × n) + φ 0 (where n = 0,
1, 2, 3). That is, it is decomposed into a 90 ° discrete phase (90 ° × n) and a remainder phase φ0. And
The 90 ° discrete phase is the output of the phase divider 23 0 °, 90
This can be realized by selecting any one of °, 180 °, and 270 ° by the switch unit 24 through the decoder 26. Further, since the remainder phase is 0 ° ≦ φ0 <90 °, it can be realized by directly controlling the reflection type phase shifter 25 from the decoder 26. As a result, the 90 ° discrete phase shifter 22 of this example is
And a single reflection type phase shifter 25 are combined, it is possible to realize an infinite phase shifter that is small in size and low in cost with a simple circuit configuration.

Next, a specific embodiment of the 90 ° discrete phase shifter 22 in the infinite phase shifter having the above-mentioned structure will be described. (First Embodiment) FIG. 2 is a block diagram showing a first embodiment of the infinite phase shifter in the present embodiment. Note that FIG.
Constituent elements common to and are attached with the same notations and an explanation thereof will be omitted. In this embodiment, the 90 ° discrete phase shifter 2 described above is used.
Two hybrid circuits 33-1, 33-2, 33
-3 and four switch parts 34 (switches 0 to 3). The switch unit 34 is an element common to the switch unit 24 of FIG.

In addition, three hybrid circuits 33-1,
33-2 and 33-3 constitute the phase divider 23 of FIG. 1, and the input signal is input to the 180 ° hybrid circuit 33 of the preceding stage.
-1 divides it into 0 ° and 180 ° signals,
90 with 90 ° hybrid circuits 33-2 and 33-3
Distribute into 4 signals every °. As for the hybrid circuit, a small and low-priced chip type is commercially available, and a small and low-priced 90 ° discrete phase shifter 22 can be configured by using this, and a reflection type phase shifter 25 can be combined. Thus, an infinite phase shifter can be realized.

(Second Embodiment) FIG. 3 is a block diagram showing a second embodiment of the infinite phase shifter in the present embodiment. The same components as those in FIG. 1 are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, the above-mentioned 90
The discrete phase shifter 22 is composed of a power splitter 42, four transmission lines (delay lines) 43, and four switch sections 44 (switches 0 to 3). Switch part 44
Are common elements to the switch unit 24 of FIG. Also,
The transmission line 43 delays the phase of the signal distributed by the power distributor 42 by a delay of (1/4) λ × n (where λ is the wavelength of the input signal and n = 0, 1, 2, 3). The data is converted and output to the switch unit 44.

Next, an actual numerical example will be described using the configuration of the above-described first embodiment (FIG. 2). 4 is shown in FIG.
FIG. 3 is a block diagram showing a first numerical example in the infinite phase shifter of FIG. 4 and shows a case where the above-mentioned phase control signal 27 is set to 45 °. In this case, the phase control signal 27 is decomposed by the decoder 26 into a 90 ° discrete phase and a remainder phase φ 0, and 90 ° discrete phase + remainder phase φ 0 = (90 ° × 0) +
45 °, that is, 90 ° discrete phase 0 ° (n = 0),
The remainder phase φ 0 = 45 °. Therefore, the 90 ° discrete phase signal is selected by the switch unit 44, and is 0 in this example.
Since ° (n = 0), switch 0 is turned on and 9
The 0 ° output of the 0 ° discrete phase shifter 22 is input to the reflection type phase shifter 25. Also, since the remainder component φ 0 = 45 °,
The reflection type phase shifter 25 is set at 45 °. Therefore,
Phase variable amount = 90 ° Discrete phase shifter output + reflection type phase shifter output = 0 ° + 45 ° = 45 °, and the set phase output φ
= 45 ° is obtained.

FIG. 5 is a block diagram showing a second numerical example in the infinite phase shifter shown in FIG. 2, and shows the case where the above-mentioned phase control signal 27 is set to 300 °. Also in this case, the phase control signal 27 is 90 ° by the decoder 26.
It is decomposed into the discrete phase and the remainder phase φ 0, and 90 ° × n + the remainder phase φ 0 = 90 ° × 3 + 30 °, that is, the discrete phase 2
70 ° (n = 3) and the residual phase φ0 = 30 °. Therefore, the 90 ° discrete phase signal is selected by the switch unit 44 and is 270 ° (n = 3) in this example, so the switch 3 is turned on and the 270 ° of the 90 ° discrete phase shifter 22 is selected.
The output is input to the reflection type phase shifter 25. Further, since the remainder component φ 0 = 30 °, the reflection type phase shifter 25 is 30 °.
Is set to. Therefore, the phase variable amount = 90 ° discrete phase shifter output + reflection type phase shifter output = 270 ° + 30 ° = 30
It becomes 0 °, and the set phase output φ = 300 ° is obtained.

As is clear from the first and second numerical examples, according to the present embodiment, the phase variable amount is 90.
Even when a reflection type phase shifter having a rotation angle of about ° is used, the phase variable amount can be expanded to 360 °, and an infinite phase shifter can be realized. FIG. 6 is a table in which the features of the infinite phase shifter of the present example as described above are summarized in comparison with the infinite phase shifters of the first and second conventional examples described above. As shown in the figure, the infinite phase shifter of this example is advantageous in comparison with the first conventional example from the viewpoint of electric characteristics such as gain variation and phase f characteristic variation when the phase is changed. The reason is that an infinite phase shifter can be realized by using only one reflection type shifter which causes a characteristic variation.

From the viewpoints of circuit scale, size, and price, the infinite phase shifter of this example is more advantageous than the second conventional example. The reason is that it is possible to realize an infinite phase shifter by using a hybrid circuit or a transmission line to configure a 90 ° discrete phase shifter at a small size and low cost without using an expensive and complicated circuit such as a ring modulator. Is. As a result, the phase shift amount is set to 360 by using the reflection type phase shifter whose phase shift amount is about 90 °.
The infinite phase shifter of ° can be realized with a simple circuit configuration, high performance, small size, and low price.

[0020]

As described above, according to the infinite phase shifter of the present invention, the phase is formed by the 90 ° discrete phase shifter having a simple structure and the single reflection type phase shifter having the phase shift amount of about 90 °. Since the variable amount can be expanded to 360 °, an infinite phase shifter can be realized with a simple circuit configuration, high performance, small size, and low cost.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration example of an infinite phase shifter according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a first embodiment of the infinite phase shifter shown in FIG.

FIG. 3 is a block diagram showing a second embodiment of the infinite phase shifter shown in FIG.

FIG. 4 is a block diagram showing a first numerical example of the infinite phase shifter shown in FIG.

5 is a block diagram showing a second numerical example of the infinite phase shifter shown in FIG.

FIG. 6 is a table in which the features of the infinite phase shifter shown in FIG. 1 are summarized in comparison with the infinite phase shifters according to the first and second conventional examples.

FIG. 7 is a block diagram showing a configuration example of a conventional reflection type phase shifter.

FIG. 8 is a block diagram showing a configuration of an infinite phase shifter configured according to a first conventional example.

[Explanation of symbols]

21 ... Input terminal, 22 ... 90 ° discrete phase shifter, 23 ...
... phase divider, 24 ... switch section, 25 ... reflection type phase shifter, 26 ... decoder, 27 ... phase control signal, 28
...... Output terminal.

Claims (7)

[Claims] 1. A 90 comprising: a phase divider for discretely distributing an input signal for each phase difference of about 90 °; and a switch section for selecting a signal distributed by the 90 ° discrete phaser.
° discrete phase shifter, and a reflection type phase shifter for inputting a signal selected by the switch section of the 90 ° discrete phase shifter and performing 90 ° continuous phase variation on the signal. Infinite phaser. 2. The infinite phase shifter according to claim 1, wherein the phase splitter includes a plurality of hybrid circuits. 3. The plurality of hybrid circuits are provided in a preceding stage 18 which outputs phase signals of 0 ° and 180 ° from an input signal.
A 0 ° hybrid circuit, and two 90 ° hybrid circuits in the subsequent stage that output phase signals of 0 °, 90 °, 180 °, and 270 ° from an output signal of the 180 ° hybrid circuit. The infinite phase shifter described in 2. 4. The infinite phase shifter according to claim 1, wherein the phase splitter includes a plurality of transmission lines. 5. The plurality of transmission lines include delay lines of 0 / 4λ, 1 / 4λ, 2 / 4λ, and 3 / 4λ with respect to a wavelength λ of an input signal. Infinite phaser. 6. A 90 ° discrete phase and a remainder phase are obtained based on a phase control signal indicating a phase variable amount, and the 90 °
2. The infinite phase shifter according to claim 1, further comprising a control circuit for selecting a switch unit by a discrete phase and controlling a phase variable amount of the reflection type phase shifter by the residual phase. 7. The infinite phase shifter according to claim 6, wherein the control circuit is a decoder.