JPH02268001A - Hybrid reflector type phase shifter - Google Patents

Abstract

PURPOSE:To reduce the overall capacitance, to set an inductance to a resonance value and to increase the quantity of a variable phase shift at a high frequency band by connecting plural varactor diodes in series with a hybrid reflector type phase shifter employing a distributed constant circuit. CONSTITUTION:Two of varactor diodes 8-11 being varactor elements whose one terminal connects to ground are connected respectively to a coupling port 3 and a transit port 4 of a hybrid reflector type phase shifter and an inductance 6 (7) made of a gold wire is connected further in series with the diode 8 (9) respectively. The inductances 6, 7 are selected to a reactance in nearly resonance with the minimum reactance of the varactor diodes 8-11. Moreover, a bias line 5 connects to a connecting point between the varactor diodes 8 and 10 and between the varactor diodes 9 and 111 via a resistor 14. Then the entire capacitance is decreased and the inductance is set to a resonance value to increase the variable phase shift quantity at a high frequency band.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hybrid reflective phase shifter using a distributed constant circuit.

[Prior Art] Conventionally, a hybrid reflective phase shifter has been proposed that utilizes applying a reverse bias to a variable capacitance element to change the capacitance. FIG. 5 is a circuit diagram of an example thereof, and FIG. 6 is a plan view of its mounted state.

In these figures, a 90'3 circuit configured with a distributed constant circuit is shown.
The dB hybrid HYB has a capacitor 12 inserted in each of the input port 1 and the isolation port 2, and is connected to the bias line 5 via a resistor 13. Also,
A varactor diode 8.9 serving as a variable capacitance element is inserted between the ground in each of the coupling port 3 and passing port 4 of the hybrid HYB, and a gold wire 6.7 as an inductance is connected in series with the varactor diode 8.9. are doing. Note that this gold wire 6.7 is selected to have a value that substantially resonates with the minimum reactance of the variable capacitance element.

[Problem to be solved by the invention]

In the conventional phase shifter described above, when constructing a phase shifter for use in a high frequency band, a varactor diode as a variable capacitance element is required to have a small capacitance. However, since the varactor diodes provided so far have a limit in reducing the capacitance when used alone, there is a problem in that the variable phase amount becomes small when used in the above-mentioned high frequency band.

For this reason, when increasing the variable phase amount, it is necessary to configure this type of phase shifter in multiple stages, which poses the problem of increasing the overall size of the configuration.

An object of the present invention is to provide a phase shifter that is small in size and has a large variable phase amount.

[Means for Solving the Problems] The phase shifter of the present invention has a 90° 3d phase shifter configured with a distributed constant circuit.
A reflection type phase shifter is constructed by connecting two or more series-connected varactor diodes as variable capacitance elements and a gold wire as an inductance in series between the compling port and passage port of the B hybrid and the ground. It consists of A bias circuit is connected to the varactor diode so that a reverse bias can be applied thereto, and the gold wire is set to have an inductance that approximately resonates with the minimum reactance of the varactor diode.

[Effect]

In this configuration, by connecting a plurality of varactor diodes in series, the overall capacitance value is reduced, and the inductance is set to a value that resonates, thereby increasing the variable phase amount in the high frequency band.

〔Example] Next, the present invention will be explained with reference to the drawings.

FIG. 1 is a circuit diagram of an embodiment of the present invention, and FIG. 2 is a plan view of its mounted state. In these figures, a 90' 3dB high frit HYB configured with a distributed constant circuit is connected to input port 1. Isolation port 2. It has a coupling boat 31 and a passing boat 4. A capacitor 12 is inserted into each of the input port 1 and the isolation port 2, and the capacitor 12 is connected to the bias line 5 via a resistor 13.

In addition, two varactor diodes 8, 10 and 9, 11 as variable capacitance elements, one end of which is connected to the ground, are connected in series to the coupling port 3 and the passage port 4, and are further configured with gold wire in series. Inductance 6.7
are connected. In this case, the inductance of the gold wire 6.7 is selected to approximately resonate with the minimum reactance of the varactor diode.

Note that a bias line 5 is connected through a resistor 14 between each varactor diode 8.10 and 9.11.

In addition, in FIG. 2, 15 is an alumina ceramic substrate, and 16 is a metal chip carrier.

Next, the operation of the phase shifter will be explained.

The high frequency signal input from input port 1 is 90°3d
13 Hybrid HYB allows campling port 3
and a passing port 4, each with a varactor diode 8
．． 10 and 9.11, are combined again at 90° 3dB hybrid HYB, and connected to isolation port 2.
It is output from At this time, varactor diodes 8, 10
and 9, 11 from the bias line 5 through the resistor 14, and these varactor diodes 8, 9.1
By changing the junction capacitance Cj of 011, the phase of the output is changed.

Here, consider a phase change of only the varactor diode due to a change in capacitance. The phase change of a varactor diode at high frequencies is shown in FIG. 3 using a Smith chart. If a reverse voltage is applied to a varactor diode at high frequency and the phase change range is AB, then the phase change when two varactor diodes are connected in series and a reverse voltage is applied is C.
It becomes D.

FIG. 4 shows the phase change when two varactor diodes are connected in series and a gold wire serving as an inductance is connected in series with the varactor diodes.

By selecting and inserting the gold wire serving as the inductance at a value that approximately resonates with the minimum reactance of the varactor diode, the phase change CD is moved to the range of EF. By connecting two varactor diodes in series and inserting a gold wire serving as an inductance into the varactor diodes, it is possible to construct a phase shifter with a large variable phase amount even at high frequencies.

[Effects of the Invention] As explained above, the present invention connects two or more varactor diodes in series to a hybrid and connects an inductance using a gold wire, thereby equivalently reducing the capacitance of the varactor diodes and achieving higher frequencies. The variable phase amount can be increased. As a result, it is not necessary to configure the phase shifter in multiple stages in order to obtain the required variable phase amount, and there is an effect that the phase shifter can be made smaller.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of an embodiment of the present invention, FIG. 2 is a plan view of the circuit shown in FIG. FIG. 5 is a circuit diagram of a conventional hybrid reflective phase shifter, and FIG. 6 is a plan view of the circuit shown in FIG. 5 in a mounted state. HYB...Hybrid, l...Input port, 2.
... Isolation port, 3... Coupling port, 4... Passing port, 5... Bias line,
6.7... Gold wire (inductance), 8-11.
...Varactor diode (variable capacitance element), 12...
Capacitor, 13.14...Resistor, 15...Alumina ceramic substrate, 16...Metal chip carrier. Figure 1 Figure 3 6.7

Claims (1)

[Claims] 1. A 90°3D circuit with input ports and isolation ports as input/output terminals, and a distributed constant circuit.
In a reflective phase shifter including a B hybrid, two or more varactor diodes as variable capacitance elements connected in series and a gold wire as an inductance are respectively connected between the coupling port and the passing port of the hybrid and the ground. connected in series, and a bias circuit is connected to the varactor diode so as to be able to apply a reverse bias,
The hybrid reflective phase shifter is characterized in that the gold wire is set to have an inductance that substantially resonates with the minimum reactance of the varactor diode.