JPS59214302A - Phase adjusting circuit - Google Patents

Abstract

PURPOSE:To eliminate the need for phase matching by connecting a diode to the intermediate output terminal of a circulator and applying a bias voltage to this diode. CONSTITUTION:An RF input signal 20 inputted to the terminal A of the circulator 4 is outputted to the intermediate output terminal C. When a -E(V) is connected to a bias terminal 10, the diode 5 turns off, and the signal at the terminal C is reflected by the diode 5 to return the circulator 4, and outputted from an output terminal B. Then when a +E(V) is connected to the bias terminal 10, the diode 5 turns on, so the signal at the intermediate output terminal C arrives at a grounding point through the diode 5 and is reflected there to reach the intermediate output terminal C of the circulator 4 through the diode 5 again, so that the signal is outputted from an output terminal B. For the purpose, the diode 5 is turned on to change a signal path by 2l, thus making phase shift.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a phase adjustment circuit that operates in a high frequency band.

Conventionally, there has been a diode phase shifter shown in FIG. 1 as a circuit of this type. In the figure, ■ is a hybrid circuit, 2 is a diode, 3 is an off-choke coil, and A and B are
, C, and D are terminals of the hybrid 1, and 10 is a bias terminal for applying a bias voltage ±E (V).

Next, the operation will be explained. The RF input signal 20 entering terminal A of hybrid 1 is % to terminals C and D, respectively.
It comes out with a power of ().Here, -E (
When V) is connected, -E (V) is applied to the diode 2 through the choke coil 3, and since it is in the OFF state, it is outputted to the terminal C and as the RF output signal 30.

The signal passes through diode 2 to the ground point, is reflected there, passes through diode 2 again, enters hybrid 1, and is output to terminal B.

In this way, when diode 2 is turned from OFF to ON, there are 2 signal paths in both directions! The length of is amplified. Utilizing this, the phase between RF IN and 0UT can be changed.

In a conventional hybrid phase adjustment circuit, there are two terminals that handle reflected signals, so the phase between these terminals must be matched. If there is a phase shift, the reflected signal returns to the signal input terminal. There were drawbacks. Also a diode”
It also had drawbacks, such as the need for two circuits of components such as choke coils.

This invention was made to eliminate the drawbacks of the conventional ones as described above. By connecting a diode to the intermediate output terminal of the circulator and applying a bias voltage to this diode, there is no need for phase matching, and the number of parts can be reduced. The purpose of the present invention is to provide a phase adjustment circuit with a small amount of noise.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Fig. 2, 4 is a circulator, 5 is a diode connected to terminal C of the circulator 4, 6 is a choke coil connected to supply bias voltage to the diode 5, 1o is a bias terminal, and 40 is a choke This is a bias circuit consisting of a coil 6 and a bias terminal 10.

No. 20 is output to intermediate output terminal C. If -E (V>) is now connected to the bias terminal 10, the diode 5 is turned off, and the signal at the terminal C is reflected by the diode 5, returns to the circulator 4, and is output from the output terminal B.

Next, when 10E (V) is connected to the bias terminal 10, the diode 5 turns on, so the signal at the intermediate output terminal C passes through the diode 5 to the ground point, is reflected there, and passes through the diode 5 again. It enters the intermediate output terminal C of the circulator 4 and is output from the output terminal B.

Therefore, by turning the diode 5 from OFF to ON, the signal path can be changed by 2ρ, and the phase can be changed.

In the above embodiment, the number of diodes is 1 (1υ), but the phase can be finely adjusted by connecting several diodes in series as shown in FIG. 3 to switch the signal reflection point.

As a similar method, diodes may be connected in parallel via a capacitor 7 as shown in FIG. Furthermore, if a four-terminal type circulator is used as in the fifth item 1, the reflected signal will not return to the RF input terminal 8 under any circumstances. 9 in the figure is a non-reflection terminator.

As described above, according to the present invention, a circulator is often installed in the middle of a circuit for the purpose of impedance matching, but by simply adding a diode and a bias circuit, it is possible to easily adjust the phase. It has the effect of configuring a circuit.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram of a conventional phase adjustment circuit, FIG. 2 is a circuit diagram of an embodiment of the present invention, and FIGS. 3 and 4. and FIG. 5 is a circuit diagram showing another embodiment of the invention. 4... Circulator, A... Input terminal, B...
Intermediate output terminal, C: output terminal, 5: diode, 6: choke coil, 8: 4-terminal circulator, 4(): bias circuit. Agent Masuo Oiwa Figure 1 Figure 2 Figure 3 Figure 5

Claims (1)

[Claims] (1) A circulator with an input terminal, an intermediate output terminal, and an output terminal, a diode connected between the intermediate output terminal of this circulator and ground with its cathode on the ground side, and a bias on the anode of this diode -1~ Phase 1 characterized by comprising a bias circuit that applies a voltage.
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