JPH06104603A - Phase shifter - Google Patents

Abstract

PURPOSE:To obtain the phase shifter by which much more number of phase states is obtained with fewer number of transmission lines and FET switches by adopting the configuration such that plural transmission lines are selected among the plural transmission lines set in parallel and transmitting a microwave to the selected transmission lines so as to obtain a phase shift. CONSTITUTION:For example, a voltage applied to control terminals 18, 19, 23, 24 of FET switches 8, 9, 13, 14 is set to OV to turn on the FET switches 8, 9, 13, 14 and a voltage applies to control terminals 20-22, 25-27 of other FET switches 10-12, 15-17 is set to -5V to turn off the FET switches 10-12, 15-17, then transmission lines 3, 4 are selected, resulting that a microwave inputted from an input terminal 1 is propagated separately to the transmission line 3 whose phase shift is theta0 and the transmission line 4 whose phase shift is theta0+theta, the microwaves are synthesized before they are outputted from an output terminal 2 and the synthesized wave is outputted with a phase shift of nearly theta0+1/2.theta. Thus, transmission lines 3-7 whose phase shifts differ from each other are selected as required to obtain a required phase shift of the microwave.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phase shifter, and more particularly to a phase shifter that selects a plurality of transmission lines to obtain a required phase.

[0002]

2. Description of the Related Art FIG. 2 is a circuit diagram showing a conventional phase shifter. In the figure, 31 is an input terminal, 32 is an output terminal, and 3 is an output terminal.
3, 34, 35 and 36 are control terminals for controlling transmission lines through which microwaves pass, 37 and 38 are transmission lines having different passing phase amounts, and 39, 40, 41 and 42 are FET switches.

Next, the operation will be described. In the conventional phase shifter configured as above, the FET switches 39 and 41
The voltage of the control terminals 33 and 34 of 0 is set to 0 V, the FET switches 39 and 41 are turned on, and the FET switches 40 and
When a voltage below pinch-off, for example, −5 V is applied to the control terminals 35 and 36 of 42 to turn off the FET switches 40 and 42, the microwave input from the input terminal 31 passes through the transmission line 37. On the other hand, FET switch 3
FET switch 40, 42 with 9, 41 turned off
Is turned on, the microwave passes through the transmission line 38. Since the transmission line 37 and the transmission line 38 have different phase amounts when passing, a phase difference occurs between the two states. In this way, the phase amount is controlled to obtain the microwave phase shift amount.

[0004]

Since the conventional phase shifter is configured as described above, the phase shifter provided with two transmission lines having different phase amounts can take only two states. Therefore, when a conventional phase shifter is used to obtain two or more states, for example, if two phase shifters having two transmission lines are connected, a phase shifter that obtains four states is obtained. Similarly, three phase shifters are phase shifters that can obtain eight states. In this way, when the number of phase shifters is increased to obtain more states, four transmission lines and eight FET switches for two phase shifters, and six transmission lines for three phase shifters. There is a problem that the number of transmission lines and FET switches increases, and the phase shifter itself also becomes large, occupying a large area.

The present invention has been made to solve the above problems, and provides a phase shifter capable of realizing more phase states by reducing the number of transmission lines and FET switches. It is an object.

[0006]

In the phase shifter according to the present invention, a plurality of transmission lines having different phases are provided in parallel, and some transmission lines are selected by FET switches connected to both ends of the transmission line. The microwave is passed through the transmission line to obtain the required amount of phase shift.

[0007]

According to the present invention, a plurality of transmission lines are selected from a plurality of transmission lines provided in parallel and a microwave is passed through the transmission lines to obtain a phase shift amount. Many phase states can be obtained without increasing the number of switches and transmission lines. Further, this also makes it possible to reduce the size of the circuit element at the same time.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1 FIG. 1 is a circuit diagram of a phase shifter according to an embodiment of the present invention,
The same reference numerals as those in FIG. 2 denote the same or corresponding portions, 1 is an input terminal, 2 is an output terminal, 3 to 7 are transmission lines provided in parallel, and the transmission line length, that is, the phase amount is θ 0, θ0 + θ, θ0 + 2θ, θ0 + 4θ, θ0 +7
θ, and the respective characteristic impedances are set to twice the characteristic impedance Z0 of the system connected to the input / output terminals, that is, 2Z0. Further, 8 to 17 are FET switches, and 18 to 27 are control terminals for controlling the microwave path. As described above, the phase shifter of this embodiment includes the five transmission lines 3 to 7 and the ten FET switches 8 to 27.

Next, the operation will be described. For example, FE
Control terminals 18, 19 of T switches 8, 9, 13, 14
The voltage of 23 and 24 is set to 0V, and the FET switch 8 and
9, 13, 14 are turned on, and the control terminals 20-22, 25 of the other FET switches 10-12, 15-17
The voltage of ~ 27 is set to -5V, and the FET switches 10-1
When 2, 15 to 17 are turned off, the transmission line 3 and the transmission line 4 are selected, and the microwave input from the input terminal 1 is transmitted to the transmission line 3 having the phase amount θ 0 and the transmission line 4 having the phase amount θ 0 + θ. The output proceeds in a divided manner, and is combined before being output from the output terminal 2 and output in a phase of approximately θ 0 + 1/2 · θ. In this way, transmission lines having different phase amounts are selected as needed to obtain the required amount of microwave phase shift.

The method for selecting any two transmission lines from the five lines 3 to 7 is as follows.
And 5,3,6,3 and 7,4 and 5,4 and 6,4 and 7,5 and 6,5 and 7,6 and 7, there are 10 ways, and the phase amount at that time is approximately θ0 + 1 / 2θ, respectively. , Θ0 + θ, θ0 + 2θ,
θ0 + 3.5θ, θ0 + 1.5θ, θ0 + 2.5θ, θ
0 + 4θ, θ0 + 3θ, θ0 + 4.5θ, θ0 +5.5
θ, and a phase shifter having 10 different phase states can be obtained.

In this way, 5 transmission lines and 10 FEs
A phase shifter equipped with a T switch can obtain 10 states when two transmission lines are selected.
Compared with the conventional phase shifter that has 12 ET switches and can obtain 8 states, one transmission line and 2 FET switches are reduced, and at least two phase states are obtained. You can get a lot.

In the above description, the case where two transmission lines are selected has been described. In addition, there are various combinations depending on how many transmission lines are selected, and there are as many phase states as the number of these combinations. Will be obtained. That is, since there are nCm ways to select m from n transmission lines, the obtained phase state is n.
It becomes Cm street.

As described above, according to the present embodiment, a plurality of transmission lines having different phases are provided in parallel, a plurality of transmission lines are selected and the microwaves are allowed to pass through the transmission lines. More phase states can be obtained without increasing the number of lines or FET switches.

[0014]

As described above, according to the phase shifter of the present invention, a plurality of transmission lines having different phases are provided in parallel,
Since a plurality of FET switches are selected from the transmission lines by using FET switches connected to both ends of the transmission line and a microwave is passed through the selected transmission lines to obtain a required amount of phase shift, a small number is required. With the FET switch and the transmission line, the more phase states can be obtained, and at the same time, the circuit element can be downsized.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a phase shifter according to an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a conventional phase shifter.

[Explanation of symbols]

 1 Input Terminal 2 Output Terminal 3 to 7 Transmission Line 8 to 17 FET Switch 18 to 27 Control Terminal 31 Input Terminal 32 Output Terminal 33 to 36 Control Terminal 37 Transmission Line 38 Transmission Line 39 to 42 FET Switch

Claims (2)

[Claims] 1. A phase shifter for adjusting the phase of a microwave, wherein a plurality of transmission lines loaded in parallel with different phase amounts and a predetermined one of the plurality of lines are selected to be connected in parallel with each other. And a plurality of switch means for performing the microwaves through the selected plurality of lines to obtain a required phase shift amount. 2. The phase shifter according to claim 1, wherein each of the switch means comprises a pair of FET switches inserted at both ends of each of the transmission lines.