JPS5991701A - Diode phase shifter - Google Patents

Abstract

PURPOSE:To miniaturize a diode phase shifter by providing a strip conductor to a face opposite to a dielectric plate face on which a metallic film forming a fin line is coated so as to bridge over a minute gap and mounting a diode on this conductor. CONSTITUTION:The metallic film 4 having the minute gap 3 is coated on one face of the dielectric plate 2. Further, the 1st two MIC lines 10 are adhered to the other face of the dielectric plate 2 so as to bridge over the minute gap 3 at the interval of an odd number of times of neary 1/4 wavelength of the fin line. Moreover, the 2nd MIC line 11 is connected to one end of the MIC line 10, and a diode 9 is connected between the line end and an equivalent short-circuit line 12. Then, a bias circuit 13 to impress a bias voltage is provided to the diode 9. The diode phase shifter is miniaturized in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention C" relates to an improvement of a diode phase shifter constructed of fin lines.

FIG. 1 shows an example of a conventional diode phase shifter constructed using fin lines. In the figure, the electric shield plate (2
), and a metal film (4) with slits (3) provided along the radio wave propagation direction is adhered to the surface of the electric shield plate (2) to form a fin line. The fin line is provided with a first branch part (5) and a second branch part (6), and these branches are connected by a first branch line (force) and a second branch line (8) of different lengths, respectively. is connected.

1/This, the first branch part (5) and the second branch part (6)
A diode (9) is connected to the branch line side of .

A bias voltage is applied to the diode (9) via a bias circuit (not shown).

In the conventional diode phase shifter shown in FIG.

By switching the bias voltage applied to the diode (9) loaded in the branch, the microwave propagation path can be switched between the first branch line (7) and the second branch line (8). Here, by setting the length of the first branch line (force) and the line length of the second branch line (8) to an appropriate length for the frequency of the propagating microwave, the required phase change, that is, the shift can be achieved. A phase shifter that obtains the phase J, 4- can be constructed as (II7).

By the way, in order to use a diode phase shifter composed of fin lines as a phase control element of a phased array antenna, the input and output of the diode phase shifter must be converted to a waveguide and connected to the antenna with the waveguide opening. There are many cases.

In a phased array antenna, a large number of inter-waveguide antennas are arranged at predetermined intervals as element antennas.
The size of the phase shifter cross section is limited.

In order to increase the degree of freedom in arranging element antennas and improve antenna performance, it is desirable that the cross section of the phase shifter be as small as possible1.
It will be done.

However, in the conventional diode phase shifter shown in Figure 1,
Since the propagation paths of different microwaves need to be set at +i/ with fin lines, the cross section of the phase shifter becomes large, which has the disadvantage of interfering with antenna arrangement.

In order to eliminate the above-mentioned drawbacks, this invention provides a strip conductor on the surface opposite to the surface of the dielectric plate covered with the metal film constituting the fin line so as to bridge the gap, and a diode is installed in the strip conductor. This is a diode phase shifter made of fin lines that is made smaller by providing means for attaching the diode and applying a bias to the diode.

The two drawings will be described in detail below.

FIG. 2 shows an embodiment of the present invention.

A metal film (4) with a slit (3) is adhered to one side of the dielectric plate (2), and the other side of the dielectric plate (2) is coated with the slit (3). (3) and two first MIC lines (one layer is attached) at an interval of approximately an odd multiple of the 1/4 wavelength of the fin line.

A second MIOIC line is connected to one end of the first MIOIC line.
C line I is connected, and a diode (9) is connected between the line end of the second MIOIC line and the two equivalent short-circuit lines (1 side).Furthermore, a bias voltage is applied to the diode (9). A redundant bias circuit 0 is provided, and a bias is supplied to the bias terminal αa from the outside.

FIG. 3 is a circuit diagram illustrating the operation of the diode phase shifter according to the invention shown in FIG. 2.

The first M, IO line (1) has the role of a transformer with a transformation ratio of N:1 that converts the fin line α9 into a microstrip line, and the second MIC line (1) has the role of a transformer with a transformation ratio of N:1. The diode-loaded line 1+61 has the following characteristics to maintain good reflection characteristics:
/4 Connected to fin lines (19) at intervals of 1 to 5 odd wavelengths.

In the circuit shown in figure ε113, the fin line (l
! If B is the susceptance looking toward the diode from the connection point between 'il and the diode-loaded line flG, then da.
By switching the polarity of the bias applied to the f-ode (9) (the bias circuit is not shown), the susceptor/s presented by the diode (9) and the second MIC
I%! 111: By appropriately selecting the length, the characteristic impedance, and the transformation ratio N of the transformer, the value of the septance B can be changed to inductivity and capacitance. Therefore, the fin line (119), which is the main line, is loaded with a susceptance or a capacitive susceptance, and in this case, the phase of the propagating microwaves leads or lags, respectively, and the diode (9 ) by switching the bias polarity applied to υ
This means that a phase shifter can be realized.

FIG. 4 shows another practical example of the present invention, in which the diode (9) is directly connected to the waveguide (11) via the shorting plate αD. Also in this embodiment, A phase shifter performance similar to that of the embodiment shown in FIG. 2 can be obtained.

Although 9 and above have shown an example in which two diode-loaded lines are used, the present invention is not limited to this, and the diode phase shifters of different phase shifters each composed of a plurality of diode-loaded lines can be driven independently from each other. It may also be used in multi-bit diode phase shifters.

As described above, in the diode phase shifter according to the present invention,
On the surface opposite to the surface of the dielectric plate covered with the metal film constituting the fin line, two strips are formed at intervals of approximately an odd multiple of the 1/4 wavelength of the fin line so as to bridge the gap in the fin line. By providing a main microstrip line, connecting a diode to the microstrip line, and switching the bias polarity applied to the diode, a diode phase shifter can be formed (14). It can be realized with the same size as the cross-sectional structure of a single line, and it can be made smaller than the conventional diode phase shifter which has a fin line branch line.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an example of the structure of a conventional diode phase shifter, FIG. 2 is a diagram showing the structure of an embodiment of the present invention, FIG. 3 is an explanatory diagram of the operation of the present invention, and FIG. FIG. 7 is a diagram showing another embodiment of the invention. In the figure, (1) is a waveguide, (2) is a dielectric plate, and (3) is a slit. (4) is the metal film, (5) is the first branch, (6) is the second
, (7) is the first branch line, and (8) is the second branch line. (9) is a diode, (II is the 10th M construction C line, (L
D is the second M, I OIJl path, 0X6 is the equivalent short circuit line, +131 is the bias circuit, Q4) is the bias terminal,
US is Finnline. Ql is a diode-loaded line, (l is a short circuit board. In addition, in Figure 2, the same or corresponding parts are indicated by the same reference numerals. Makoto Kazuno - Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] An electric shield plate is arranged approximately in the center of the wide surface of the high-frequency wave sensor parallel to the electric field, and a metal film with a narrow gap in the direction of radio wave propagation is adhered to one side of the electric shield plate. In the diode phase shifter constructed using a fin line consisting of the above 11 rivers 1! Attach two strip conductors so that ii is 1 quotient and at an interval of approximately 1/4 wavelength t) of the fin line, and one end of each of the two strip conductors. A diode phase shifter, comprising means for connecting a diode to the diode and applying a bias voltage to the diode.