JPH09232802A - Hybrid reflection type phase shifter - Google Patents

Abstract

Kind Code: A1 Abstract: A reflection type phase shifter including a 90 degree 3 dB hybrid and a varactor diode as a variable capacitance element, and a phase shifter in which passage loss does not change with phase change is provided. SOLUTION: In a reflection type phase shifter comprising 90 degree 3dB hybrids a and b constituted by distributed constant circuits, a coupling port 6a and a pass port 7 of the hybrid a are provided.
a hybrid reflection type phase shifter in which variable capacitance elements 8a and 9a are connected between a and ground;
Between the coupling port 6b and the passage port 7b and the ground and the variable capacitance elements 8b and 9b and
Two second hybrid reflection type phase shifters in which transmission lines 12 and 13 having a length of two wavelengths or less are connected in series are connected in series as two sets. The amount of change in the passing loss of the first phase shifter and the amount of change in the passing loss of the second phase shifter cancel each other out, and the phase shifter does not change in the passing loss due to the change in the phase.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hybrid reflection type phase shifter, and more particularly to a hybrid reflection type phase shifter using a distributed constant circuit used in communication equipment.

[0002]

2. Description of the Related Art An example of a conventional hybrid reflection type phase shifter of this type is disclosed in, for example, Japanese Patent Application Laid-Open No. 2-268001, and its circuit configuration is shown in FIG.

Referring to FIG. 3, the portion indicated by reference numeral a is
This is a 90 degree 3 dB hybrid (HYB) composed of a distributed constant circuit, and this 90 degree 3 dB hybrid a
Consists of an input port 4, an isolation port 5, a coupling port 6, and a passage port 7. Small-capacity varactor diodes 8 and 9 each having one end connected to the ground are connected to the coupling port 6 and the passage port 7, respectively.

In the figure, reference numeral 3 is a bias terminal, which is a resistor 17,
A reverse bias is applied to the varactor diodes 8 and 9 via 18. The input port 4 and the isolation port 5 are connected to the input terminal 1 via capacitors 15 and 16, respectively.
And the output terminal 2.

Varactor diodes 8 and 9 serving as variable capacitance elements connected to one end of each of the coupling port 6 and the passage port 7 of the 90 ° 3 dB hybrid a.
And are connected via gold wires 23 and 24 as inductances. The gold wires 23 and 24 are selected to have a value that substantially resonates with the minimum reactance of the variable capacitance element.

[0006]

In the above configuration, the inductance of the gold wires 23 and 24 is designed to resonate with the minimum reactance of the varactor diodes 8 and 9,
The variable phase amount of the phase shifter is large. However, the reflection coefficient of the varactor diode changes with the capacitance change due to the value of the equivalent resistance Rs of the diode.
As a result, a change in the passage loss of the phase shifter cannot be avoided with the change in the phase.

FIG. 4 is a Smith chart showing a phase change of a general varactor diode due to an applied voltage at a high frequency. The phase change range at this time is AB.
Then, the reflection coefficient at the point B is smaller than the reflection coefficient at the point A, which increases the passing loss of the phase shifter.

The phase shifter composed of such a 90-degree 3 dB hybrid and a varactor diode as a variable capacitance element is used for high-frequency output synthesis and the like, but there is a change in the passage loss due to the phase change as described above. Therefore, it is necessary to perform adjustment by the variable attenuator to correct it.

Therefore, the present invention has been made to solve such problems of the prior art, and its purpose is to eliminate the passage loss due to the phase change and to eliminate the need for adjustment by the variable attenuator. And to provide a hybrid reflection type phase shifter.

[0010]

SUMMARY OF THE INVENTION A hybrid reflective phaser according to the present invention comprises an input port, an isolation port, a hub lid provided between the input port and the isolation port, and a cup of the hub lid. First hybrid reflection type phase means having a variable capacitance element connected between each of the ring port and the passage port and the reference potential point, an input port, an isolation port, these input ports and an isolator A hub lid provided between the hub lid and a coupling port, a coupling port and a passage port of the hub lid, and a reference potential point, respectively, and a variable capacitance element and a length of 1/2 wavelength or less of a used frequency. Second hybrid reflective phase means having a series circuit with the transmission line of the first hybrid The isolation port of the reflection-type phase device is characterized in that connected to the input port of the second hybrid reflection-type phase device.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The operation of the present invention will be described. 2
The individual hybrid reflection type phase shifters are connected in series (one output is connected to the other input), and are canceled by a loss change caused by a phase change by one phase shifter.

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

FIG. 1 is a circuit configuration diagram of an embodiment of the present invention, and the same portions as those in FIG. 3 are designated by the same reference numerals. In FIG. 1, the hybrid a has an input port 4a, an isolation port 5a, a coupling port 6a, and a passage port 7a. Varactor diodes 8a and 9a are connected between each of the coupling port 6a and the passage port 7a and the ground.

On the other hand, the hybrid b has an input port 4b,
Isolation port 5b, coupling port 6
b, passing port 7b. A series circuit of a varactor diode 8b and a transmission line 12 having a length of ½ wavelength or less of a signal is connected between the coupling port 6b and the ground, and between the pass port 7b and the ground.
A series circuit of the varactor diode 9b and the transmission line 13 is connected.

The isolation port 5a of the hybrid a and the input port 4b of the hybrid b are commonly connected, and the two phase shifters are connected in series.

The input terminal 1 is connected to the input port 4a via the capacitor 15, and the output terminal 2 is connected to the capacitor 1
It is connected to the isolation port 5b through 6. The bias terminal 3 is for applying a bias voltage to each varactor diode via the resistors 17 to 19.

FIG. 2 is a plan view of the circuit of FIG. 1 in a mounted state, in which 20 is an alumina ceramic substrate and 21 is a via hole for a ground contact.

The operation of the phase shifter configured as above will be described. The high-frequency signal input from the input terminal 1 is input to the input port 4a of the hybrid a, divided into the coupling port 6a and the passage port 7a, reflected by the varactor diodes 8a and 9a, and again synthesized by the hybrid a, It is output to the isolation port 5a. Here, the passage loss of the first phase shifter is determined by the reflection coefficients of the varactor diodes 8a and 9a.

Next, the high frequency signal is the hybrid b in the next stage.
Input to the input port 4b, and the coupling port 6b
And a passage port 7b, and a varactor diode 8
It is reflected by b and 9b, is again synthesized by the hybrid b, is output to the isolation port 5b, and is output to the output terminal 2. Here, the passage loss of the second phase shifter is
It is determined by the reflection coefficient of the circuit in which the varactor diodes 8b and 9b and the transmission lines 12 and 13 are connected in series.

Here, the phase change of a single varactor diode when a voltage is applied is as shown in AB of FIG.
On the other hand, the phase change of the circuit in which the varactor diodes 8b and 9b and the transmission lines 12 and 13 are connected in series is C in FIG.
The lengths of the transmission lines 12 and 13 are determined so as to be −D. As a result, the amount of change in the reflection coefficient associated with the phase change of A-B cancels out the amount of change in the reflection coefficient associated with the phase change of CD, so that the phase shifter of FIG. It is possible to reduce the change in passing loss when going down.

A method of setting the lengths of the transmission lines 12 and 13 will be described. In FIG. 5, a circular arc CD is drawn symmetrically with the circular arc AB, the angle θ of the angle AOC is calculated, and the used signal frequency (high frequency) is obtained. ), The length of θ / π may be set.

[0022]

As described above, according to the present invention,
In a reflection type phaser including a 90 degree 3 dB hybrid, a first hybrid reflection type phaser in which a varactor diode as a variable capacitance element is connected between a hybrid coupling port and a passing port and a ground, and a hybrid cup A second hybrid reflection type phase shifter in which a varactor diode and a transmission line having a length equal to or less than a half wavelength of the used high frequency are connected in series between the ring port and the passing port and the ground, and one pair is composed of two. By connecting in series, there is an effect that a phase shifter in which the passage loss does not change with the change in phase can be manufactured.

[Brief description of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention.

FIG. 2 is a mounting plan view of a circuit according to an embodiment of the present invention.

FIG. 3 is a circuit diagram showing an example of a conventional hybrid reflection type phase shifter.

FIG. 4 is a diagram showing a phase change range of a varactor diode.

5 is a diagram showing a method of designing the length of a transmission line in the circuit of FIG.

[Explanation of symbols]

 a, b Hybrid 1 Input terminal 2 Output terminal 3 Bias terminal 4a, 4b Input port 5a, 5b Isolation port 6a, 6b Coupling port 7a, 7b Passing port 8a, 8b, 9a, 9b Varactor diode 12, 13 Transmission line 15 , 16 capacitors 17 to 18 resistors 20 alumina ceramic substrate 21 via holes

Claims (3)

[Claims] 1. An input port, an isolation port, a hub lid provided between the input port and the isolation port, and each of a coupling port and a pass port of the hub lid and a reference potential point. First hybrid reflective phase means having a variable capacitance element respectively connected to the input port, an input port, an isolation port, a hub lid provided between the input port and the isolation port, and the hub lid. Is provided between each of the coupling port and the passage port of and the reference potential point,
A second hybrid reflection type phase means having a series circuit of a variable capacitance element and a transmission line having a length equal to or less than 1/2 wavelength of a used frequency; and an isolation port of the first hybrid reflection type phase means. Is connected to the input port of the second hybrid reflection type phase means. 2. The hybrid reflection according to claim 1, wherein the transmission line is set to a length that substantially cancels a passage loss caused by a phase change of the first hybrid reflection type phase means. Type phaser. 3. The hybrid reflection type phase shifter according to claim 1, wherein each hybrid of the first and second hybrid reflection type phase means is a hybrid of 90 degrees 3 dB.