JPS5949002A - Semiconductor phase shifter - Google Patents

Abstract

PURPOSE:To prevent the deterioration of characteristics due to the variance of the FET characteristics, by using a low deadline type semiconductor phase shifter in which the drain and the gate of an FET are separated from each other with the source used in common. CONSTITUTION:An FET11 contains drain electrodes 12 and 13 as well as gate electrodes 14 and 15. In addition, a common source electrode 16 is connected to an earth conductor 2 by a pierced conductor 9. A conductor 17 is provided between branch lines 4 and then connected to the conductor 2 through the conductor 9. These lines 4 are connected to a main line 3 with a space of about 1/4 wavelength. The space between electrodes 12/14 and the electrode 16 is extremely reduced as well as between electrodes 12/13 and the electrode 16 respective by, to obtain similar characteristics among these electrodes. As the electrodes 12 and 13 are set extremely close to each other, the lines 4 are set close to each other. In this connection, the conductor 17 is provided to reduce as less as possible the connection between both lines 4. This arrangement enables the use of the FET11 containing the electrodes 12 and 13 put extremely close to each other, which is equal to the use of an FET that has an equal impedance to the microwaves between electrodes 12/16 and 13/16. Therefore this semiconductor phase shifter can prevent the performance deterioration due to the variance of the FET characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a loaded line type semiconductor phase shifter configured on a semiconductor substrate and used as an FzTi control element to control the phase of microwaves.

First, a conventional semiconductor phase shifter will be explained.

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 a ground conductor, (3) is the main line of a ficro strip line constructed together with the ground conductor (2), (4111″i is also a branch line, (5 ) is FBT, (61 is the drain electrode of FnT (51), and (7) is also the source electrode.

(8) is the same gate electrode, +9) is the source electrode sand (7)
and the through conductor connecting the ground conductor (2), Gl is the gate'
This is a bias circuit based on a microstrip line for applying bias to the @ pole (8).

The main line (3) has two branch lines (
4) is connected, and the other end of the 9-branch line (4) is connected to an FET (
5) is connected. A semiconductor phase shifter having such a configuration changes the impedance between the drain and the source to the microwave by changing the bias voltage applied to the gate electrode (8).
) and the main line (3) when looking at the FIT (5) side from the connection point at the same time from capacitive to inductive, or vice versa. Changing the phase of the microwave propagating through the main line from K, It operates as a phase shifter.

However, the load line type semiconductor phase shifter has two F
If there is a difference in the ET characteristics, the phase characteristics and loss characteristics 9 reflection characteristics of the phase shifter will deteriorate.

Therefore, it is required that the characteristics of the two FKTs be the same, but in general, even when they are constructed on the same semiconductor substrate, there are variations in %Note between different F' E T l'JJs.
This has been a problem in manufacturing this type of semiconductor phase shifter.

In order to solve the above problem, the present invention is applied to an FIT loaded line type semiconductor phase shifter having a structure in which the toe train and gate of - FF1T are separated and the source is shared.
The purpose is to eliminate the deterioration of the phase shifter characteristics due to unevenness in the percentage characteristics of the FETs, and will be explained in detail below.

FIGS. 2 and 3 are configuration diagrams of a semiconductor phase shifter showing an embodiment of the present invention. Furthermore, FJi! used here!
T (1fii Divide the drain and gate into two, and separate the first drain electrode 02 and the second drain electrode 0
The common source electrode OQ is connected to the ground conductor (2) by a penetrating conductor (9), and the source is common to the common source electrode OQ.
A conductor 0η is arranged between the two branch lines (4) and connected to the ground conductor (2) by a nine-through conductor (9) in a virtual configuration.

Moreover, the first drain electrode 02 is connected to one branch line (4)
In addition, the second drain electrode 03 is connected to the other branch line (4
), and one end of these branch lines (4) is connected to the main line (3) at an interval of approximately 1/4 wavelength.

Furthermore, the first gate electrode (tL) and the second gate electrode (l
A bias circuit for applying a bias voltage to the gate electrode is connected to (f).

In order to change the bias voltage applied via the bias circuit 111, the semiconductor phase shifter having the above configuration is configured so that the bias voltage applied through the bias circuit 111 is changed between the first drain electrode 0 and the source electrode (l [9, and the second drain electrode and the source electrode aQ). The impedance shown to the microwave changes, and the susceptance value reversed to the main line (3) at approximately 1/4 wavelength intervals changes. It works as a phase shifter.

To further describe the effect of the conductor (171) of the semiconductor phase shifter according to the present invention, the gate electrode I of the first drain \li !'i [12, 2K 1 in the FET (u)
and a common source electrode +IQ and a second drain electrode α3.
The second gate electrode and the common source electrode are fabricated in extremely close positions and have similar characteristics, but the first electrode and the common source electrode are fabricated in very close positions, and have similar characteristics. Since the drain electrodes 0z and a of No. 2 are very close to each other, the branch lines (4) connected to them are also close to each other. - At this time, if there is microwave coupling between the two branch lines (4), the characteristics as a semiconductor phase shifter will deteriorate. As a countermeasure, both branch lines B (
In order to reduce the coupling between 4+ and 4+ as much as possible, a conductor 07) connected to the ground conductor (2) via a through conductor (9) is arranged. This i1μ, the first drain electrode H and the drain electrode of Ryo2.
It is practically possible to use the FET (11) 1 in which the electrodes αj are very close to each other, and it is also possible to use microwaves between the first drain electrode and the source electrode and between the second drain electrode and the source electrode. FBTV with equal impedance! - It means that it can be used. As a result of the above, the loaded line type semiconductor phase shifter according to the present invention can prevent performance deterioration due to the unevenness of FET characteristics K.The above description is based on the case where the main line (3) is linearly oriented. However, the present invention is not limited to this, and may be applied to a semiconductor phase shifter in which the main line (3) between each branch line (4) is bent to reduce the size in the propagation direction.

Furthermore, it is natural to apply the semiconductor phase shifter according to the present invention to a multi-bit digital semiconductor phase shifter in which the semiconductor phase shifter according to the present invention is continuously connected. The two branch lines, which are connected to the main line at 4 wavelength intervals, are suppressed from coupling caused by their close proximity to each other near the FED, and FETs with similar characteristics can be loaded at each end, resulting in good transfer of characteristics. A phase converter can be realized, and its industrial value is extremely high.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing the structure of a conventional loaded line type semiconductor phase shifter, and FIGS. 2 and 3 are perspective views showing an embodiment of the present invention. In the figure, (1) is a semiconductor substrate, (2) is a base body, (3) is a pressure line, (4) is a branch line, (511"111' E
'11', +61i-t tray 7 electric, ,
(7) B y - cap pole, (8in game) 'rH
IM e (9n, [ is a conductor, aυ is a bias circuit,
(LDfl If"E '1', (lal-,
, L is the first drain electrode, α is the second drain electrode, ■ is the first gate electrode, (151μ is the second gate electrode, 00μ is the trace electrode, and Qη is the conductor. In addition, in Figure 9, the same or corresponding parts are indicated with the same reference numerals. Agent Makoto Kuzumachi - Figure 1 Figure 2

Claims (1)

[Claims] FF1 on a microstrip line configured on a semiconductor substrate.
In a semiconductor phase shifter connected with Ti. One end of two branch lines made of microstrip lines are connected to the main line made of microstrip lines at approximately 1/4 wavelength intervals, and the other ends of the two branch lines are connected to P.
The first drain electrode and the second train electrode of the ET
1 connect it and the first and above! ! The source electrode of the FET which is provided in common with the valley drain electrode of No. 2 is grounded, and the first gate electrode between the first drain electrode and the source electrode of the FIT and between the drain electrode and the source electrode of No. 2 are grounded. 1. A semiconductor phase shifter having 6+ stages for applying a bias to a second gate electrode of a semiconductor phase shifter, and having a grounded substrate arranged on a semiconductor substrate between both branching lines.