JPH01202007A - monolithic microwave phase shifter - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a circuit scheme for a monolithic microwave phase shifter.

(Prior art) In recent years, microwave solid-state circuits have been developed using monolithic microwave integrated circuits (hereinafter referred to as MMICs), which integrate semiconductor elements such as input/output matching circuits and FETs on semi-insulating substrates such as GaAs.
(abbreviated as ) technology is becoming more widely used because it allows devices to be made smaller and cheaper. In particular, phase shifters using MMIC technology have realized miniaturization of devices widely used in phased array antennas and the like.

FIGS. 7 and 8 are circuit configuration diagrams of conventionally used MMIC phase shifters. FIG. 7 shows a loaded line phase shifter, in which one end of a matching distributed constant line (2a, 2b) is connected to both ends of a 1/4 wavelength distributed constant line 1. Railway tracks (2a, 2
Switch FETs (3a, 3b) are connected to the other end of b). Further, one end of the 1/4 wavelength distributed constant line 1 is connected to an input terminal 4°, and the other end is connected to an output terminal 5. Furthermore, a control signal input terminal 6 is connected to the gates of the switch FETs (2a, 2b), and a control signal Q is supplied thereto.

In this phase shifter, the control signal Q causes the FET (
3a, 3b) are turned on and off at the same time,
A desired amount of phase shift can be obtained by changing the passing phase of the input signal. Although this type of loaded line phase shifter has a good design and requires only one control signal, it
In this case, there was a drawback that the chip size became large because a 1/4 wavelength distributed constant line was used.

Figure 8 shows a low-pass bypass switching type phase shifter, in which FETs (11a to 11f) are used as circuit switching switches to supply control signals (Q, Q) with different polarities to each. , inductor (12a
, 12b), a low-pass filter by capacitor 13 and a capacitor (14a).

14b), the inductor 15 forms a bypass filter. That is, the phase shift circuit is switched between a low-pass filter and a bypass filter using control signals Q and Q, and a desired amount of phase shift is obtained based on the difference in passing phase at this time.

Although such a low-pass bypass switching type is inferior in design efficiency to the loaded line type, it is possible to miniaturize the chip because it uses lumped constant elements. However, two control signals with different polarities are required, and MMIC
The disadvantage is that the peripheral area tends to be complicated with control signal terminals and the like.

(Problems to be Solved by the Invention) As mentioned above, conventional monolithic microwave phase shifters require one control signal, but the chip size is large, or the chip size is small, but requires two control signals. There were some pros and cons.

SUMMARY OF THE INVENTION An object of the present invention is to eliminate such drawbacks and provide a monolithic microwave phase shifter that is small in size and requires only one control signal.

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention includes a plurality of inductors connected in series, one of which is an input end and the other is an output end,
a first switch element connected between the input terminal and the output terminal; a capacitor connected between each connection point of the inductor and ground; a second inductor connected in parallel with the capacitor and resonating with the capacitor; A monolithic microcontroller comprising an inductor circuit consisting of the second inductor and a second switch element connected in series, and a control terminal that supplies a control signal to simultaneously control the first switch element and the second switch element. wave phase shifter.

Further, a plurality of capacitors connected in series, one of which is an input terminal and the other of which is an output terminal, a first switch element connected between the input terminal and the output terminal, and a connection point between each of the capacitors and the ground. a capacitor circuit comprising a connected inductor, a second capacitor connected in parallel with the inductor and resonating with the inductor, and a second switch element connected in series with the second capacitor, the first switch element and and a control terminal for providing a control signal that simultaneously controls a second switch element.

(Function) In the monolithic microwave phase shifter of the present invention, by simultaneously switching the switching element into the on state and the off state using one control, the switching element is switched between the low pass filter (or bypass filter) and the input/output shorted state. A desired amount of phase shift is obtained by the passing phase difference between the two.

(Example) Hereinafter, one example of the present invention will be described with reference to the drawings. FIG. 1 is a circuit configuration diagram showing an embodiment of the monolithic microwave phase shifter of the present invention, and includes an inductor (21a) of lumped constant elements connected in series.

A switching FET 22 is connected as a first switching element to both ends of the inductor (21a, 21b).
A capacitor 23 and an inductor 24 are connected in parallel between each connection point of 21b) and ground. Further, a switching FET 25 is connected in series to the inductor 24 as a second switching element. Furthermore, the same control signal is supplied to the switch FETs (22, 24) from the same control terminal 26, and one end of the series-connected inductors (21a, 2lb) is connected to the input terminal 27. The other end is an output terminal 28.

Here, when the control signal Q supplied to the control terminal 26 becomes 110 II, the switch FET (22,
24) are each turned off, and the phase shifter becomes a low-pass filter as shown in FIG. 2(a), which constitutes the reference state of the phase shifter.

Next, when the control signal Q becomes "1", the switch FETs (22, 24) are turned on, and the inductor (lla) is turned on.

11b) is short-circuited by the switch FET 22, and by selecting the inductor 24 to resonate in parallel with the capacitor 23 at the desired frequency f0, the phase shifter is configured as shown in FIG. 2(b).
), which forms an input/output short circuit, which constitutes the phase shift state of the phase shifter.

In other words, in the standard state, the inductor is set so that the low-pass filter forms a delay circuit with fo.

If the value of the capacitor C is set so as to satisfy the Rα mouth φ cos (θ / 2 - θ; the passing phase R of the low-pass filter; the termination condition of the low-pass filter), the phase shift amount ■ will be approximately ■ -t2
It is expressed as πfoF.

Further, the specifications such as the gate width of the FET 22 may be selected so that the insertion loss of the low-pass filter and the insertion loss in the phase shift state are equal to each other. As described above, since the present phase shifter uses lumped constant elements, it is possible to realize a phase shifter with a small chip size and only one control signal.

By the way, in this embodiment, a one-stage T-type low-pass filter was used, but as shown in FIG. capacitor 3 connected in parallel with
It can also be constructed using a multi-stage low-pass filter composed of 3 and an inductor 34. - Furthermore, as shown in FIG. 4, a π-type low-pass filter can be used, which is composed of a capacitor 43 and an inductor 44 connected in parallel between both ends of an inductor 41 and ground, respectively.

Furthermore, the phase shifter of the present invention can be configured using a bypass filter instead of a low-pass filter. For example, as shown in Figure 5, capacitors connected in series (
51a, 51b) with switch FET 52 at both ends.
and an inductor 53 connected in parallel between each connection point of the capacitors (51a, 5lb) and the ground.
and a capacitor 54. In addition, a switch FET 55 is connected to the capacitor 54, and two switch FE
The same control terminal 56 is connected to each of T(52, 55). Furthermore, capacitors (51a,
A T-type phase shifter is constructed with one end of the input terminal 57 serving as an input terminal 57 and the other end serving as an output terminal 58.

In the phase shifter having the above configuration, when the control signal Q supplied to the control terminal is "11", the PETs (52, 55> are each turned on, which constitutes the reference state of the phase shifter, and the control signal Q is "11"). FET at 0°
(52, 55) are each turned off, in this case constituting the phase shift state of the phase shifter.

Further, as shown in FIG. 6, a phase shifter can be constructed using a π-type low-pass filter composed of an inductor 63 and a capacitor 64 connected in parallel between both ends of a capacitor 61 and ground, respectively.

Furthermore, it is clear that similar results can be obtained even if the above-described bypass filter type phase shifter has a multi-stage configuration.

Further, in the above embodiments, FETs are used as switching elements, but diodes may also be used.

[Effects of the Invention] As described above, according to the present invention, since the phase shift amount is changed by switching the switch elements with one control signal, it is possible to provide a monolithic microwave phase shifter with a small chip size.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of a monolithic microwave phase shifter according to the present invention, FIGS. 2(a) and 2(b).
) is a diagram showing the operation of the monolithic microwave phase shifter of FIG. 1, FIGS. 3 to 6 are circuit diagrams showing other embodiments of the present invention, and FIGS. FIG. 2 is a circuit diagram showing a microwave phase shifter. 21a, 21b, 24.53--inductor 22.2
5,52.55...... Switch FET2
3.51a, 51b, 54-capacitor 26.56...
・・・・・・・・・・・・・・・・・・・・・・・・
Control signal agent Patent attorney Nori Ken Yudo Sanno - Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7

Claims (2)

[Claims] (1) A plurality of inductors connected in series with one end as an input end and the other as an output end, a first switch element connected between the input end and the output end, and a connection point between each of the inductors and ground. an inductor circuit consisting of a capacitor connected to the capacitor, a second inductor connected in parallel with the capacitor and resonating with the capacitor, and a second switch element connected in series with the second inductor; and the first switch element. and a control terminal for supplying a control signal for simultaneously controlling the second switch element. (2) A plurality of capacitors connected in series with one end as an input end and the other as an output end, a first switch element connected between the input end and the output end, and a connection point between each of the capacitors and ground. a capacitor circuit consisting of an inductor connected to the inductor, a second capacitor connected in parallel with the inductor and resonating with the inductor, and a second switch element connected in series with the second capacitor; and the first switch element. and a control terminal for supplying a control signal for simultaneously controlling the second switch element.