JPS633207Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to improving the performance of a semiconductor phase shifter that is constructed on a semiconductor substrate and uses an FET as a control element to control the phase of microwaves.

Furthermore, this invention relates to a loaded line type among various types of semiconductor phase shifters.

FIG. 1 shows an example of the structure of a conventional loaded line type semiconductor phase shifter. In the figure, 1 is a semiconductor substrate, 2
is the ground conductor, 3 is the main line of the microstrip line configured together with the ground conductor 2, 4 is the branch line as well, 5 is the FET, 6 is the drain electrode of the FET 5, 7
is the same source electrode, 8 is the same gate electrode, and 9 is the same source electrode.
is a through conductor connecting the source electrode 7 and the ground conductor 2,
10 is a bias circuit consisting of a microstrip line for applying a bias to the gate electrode.

Two branch lines 4 are connected to the main line 3 at approximately 1/4 wavelength intervals, and an FET 5 is connected to the other end of the branch line 4.
This is a configuration in which the two are connected. In the semiconductor phase shifter having such a configuration, by changing the bias voltage applied to the gate electrode 8, the impedance shown between the drain and source to microwaves is changed, and the connection point between the branch line 4 and the main line 3 is changed. From FET5
By simultaneously changing the impedance viewed from the side from capacitive to inductive or vice versa, the phase of the microwave propagating through the main line is changed, and it operates as a phase shifter.

By the way, in a loaded line type semiconductor phase shifter, if there is a difference in the characteristics of two FETs, the phase characteristics, loss characteristics, and reflection characteristics of the phase shifter deteriorate. Therefore, it is required that the characteristics of the two FETs be the same, but in general, there are variations in characteristics between different FETs even when they are configured on the same semiconductor substrate.
This has been a problem in manufacturing this type of semiconductor phase shifter.

This idea solves the above problem by using one
The purpose is to use a FET with a configuration in which the drain and gate of the FET are separated and the source is common in a loaded line type semiconductor phase shifter, and to eliminate deterioration of the phase shifter characteristics due to uneven characteristics of the FET. The drawings will be explained in detail below.

Figures 2 and 3 are examples of this invention.
The FET 11 used here has a drain and a gate divided into two, each forming a first drain electrode 12, a second drain electrode 13, a first gate electrode 14, and a second gate electrode 15, and the source is common. In this configuration, the common source electrode 16 is connected to the ground conductor 2 by a through conductor 9.

Further, the first drain electrode 12 is connected to one branch line 4, and the second drain electrode 13 is connected to the other branch line 4, and one end of these branch lines 4 is connected to the main line 3 by approximately 1/2. They are connected with a spacing of 4 wavelengths.

Further, a bias circuit 10 for applying a bias voltage to the gates is connected to the first gate electrode 14 and the second gate electrode 15.

The semiconductor phase shifter having the above configuration includes a bias circuit 10
By changing the bias voltage applied through the , the impedance shown to microwaves between the first drain and source and between the second drain and source changes, and the main line 3 is loaded at approximately 1/4 wavelength intervals. Since the susceptance value changes, the phase of the microwave propagating through the main line 3 changes, and the main line 3 operates as a phase shifter.

In the phase shifter configured in this way, FET11
A source electrode 16 common to the first drain electrode 12 and the first gate electrode 14 and a source electrode 16 common to the second drain electrode 13 and the second gate electrode 15 are fabricated in extremely close positions. Each has similar characteristics. Therefore, the impedance shown to microwaves between the first drain and source and between the second drain and source becomes equal, and the loaded line type semiconductor phase shifter manufactured using this FET 11 has the same characteristics as the FETs. It is possible to prevent performance deterioration due to

Although the above description has been given of the case where the main line is arranged linearly, the present invention is not limited to this and may be applied to a semiconductor phase shifter in which the main line 3 between the branch lines 4 is bent to reduce the size in the propagation direction, as shown in FIG.

Further, the semiconductor phase shifter according to this invention may be used as a multi-bit digital phase shifter by cascade connection, and other types of semiconductor phase shifters such as a switched drain type semiconductor phase shifter 17 as shown in FIG. It may also be used in cascade connection with a phaser.

As described above, in the semiconductor phase shifter according to this invention, FETs with similar characteristics can be loaded at the tips of two branch lines connected to the main line at approximately 1/4 wavelength intervals, so that FETs with good characteristics can be installed. A phase shifter can be realized.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the structure of a conventional loaded line semiconductor phase shifter, Figs. 2 and 3 are perspective views showing an embodiment of the invention, and Figs. 4 and 5 are perspective views of the invention. It is a perspective view showing other examples by. In the figure, 1 is a semiconductor substrate, 2 is a ground conductor, 3 is a main line, 4 is a branch line, 5 is an FET, 6 is a drain electrode, 7 is a source electrode, 8 is a gate electrode, 9 is a through conductor, and 10 is a bias circuit , 11 is FET, 12
is a first drain electrode, 13 is a second drain electrode, 14 is a first gate electrode, 15 is a second gate electrode, and 16 is a common source electrode. In the drawings, the same or corresponding parts are designated by the same reference numerals.

Claims (1)

[Scope of utility model registration request] In a semiconductor phase shifter formed by connecting an FET configured on a semiconductor substrate and a microstrip line configured on the semiconductor substrate, the main line consisting of the microstrip line is connected at approximately 1/4 wavelength intervals,
One end of two branch lines also made of microstrip lines is connected, and the other ends of the two branch lines are connected to the first drain electrode and the second drain electrode of the FET, respectively. 1st and 2nd
For each drain electrode of
The source electrode of the FET is grounded, and the first gate electrode and the second gate electrode between the first drain and source of the FET are grounded.
A semiconductor phase shifter comprising means for applying a bias voltage to a second gate electrode between the drain and source of the semiconductor phase shifter.