JPH02164101A - diode phase shifter - Google Patents

Abstract

PURPOSE:To apply impedance conversion between a main line and a pad gradually and to reduce the deterioration in the VSWR by forming a conversion section between a main line and a square pad with a DC cut capacitor mounted thereto. CONSTITUTION:A drive bias voltage is supplied externally from a bias pad 10 and fed to a diode 3 via the main line and a load line. In this case, the drive bias voltage is turned on/off to vary the susceptance value of a device line 8 when viewing from the main line 7 and also the transmission phase. The difference between transmission phases is a phase shift quantity. Moreover, since a DO cut capacitor 4 exists to the input and output side, the drive bias voltage does not give effect on other circuit connecting to the phase shifter. Since the connection part between the main line 5 and the pad is formed tapered, gradual impedance conversion is attained and reflection is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improving the characteristics of a diode phase shift stop used for phase shift control of an electronically controlled antenna.

[Conventional technology]

FIG. 3 is a perspective view showing an example of a conventional diode phase shifter, which is called a loaded line phase shifter.

In the figure, (1) is a ground conductor such as Kovar, (2) is a substrate substrate such as ceramic, (3) is a diode, (4) is a DC cut capacitor, (5) is the main 411 omitted, and (7) is The main line of the phase shifter, (8) is the loading line, (9)
is a phase delay circuit consisting of (7) and (8), (IQ is a bias pad for externally receiving the drive bias voltage of diode (3), (Ill is a 174 wavelength low impedance line, and is the main line (5) A 174-wavelength high-impedance line to microwave the connection part with It is a square pad for mounting.

Next, the operation will be explained. A loaded line type diode phase shifter changes the impedance of the diode (3) by changing the drive bias voltage of the diode (3), and the loading 4 as seen from the main IIt path (7) of the phase shifter.
1i # (81 susceptance value is changed, and the transmission phase difference at that time is changed to a desired phase shift amount.

The wA drive bias voltage is applied to one electrode of the diode (3) from the bias pad. Bias circuit (
[) is between 174 wavelength low impedance LI circuit and 1
Due to the combination of the 74-wavelength high impedance S path ((2)), it is in a microwave 0PEN state when viewed from the main line (5).

DC cut capacitors for blocking the drive bias voltage are mounted on the input and output sides of the main line (5).

[Problem to be solved by the invention]

A conventional diode phase shifter has a DC cut capacitor (4) mounted on the input side and output side, and a DC cut capacitor (4) mounted on the input side and output side.
4) Due to the influence of the square pad ■ that is mounted, the VSWR
There was a problem in that the phase shift amount became large and the phase shift amount characteristics deteriorated accordingly.

This invention was made to solve the above-mentioned problems, and aims to minimize the influence of reflection by a DC cut capacitor.

[Means to solve the problem]

The diode phase shifter according to the present invention has a tapered converting section between the rectangular pad (+4) on which the DC cut capacitor (4) is mounted and the main line (5).

[For production]

The diode phase shifter in this invention gradually transforms the impedance between the main line and the pad by tapering the conversion part between the square pad on which the DC cut capacitor is mounted and the main line. To reduce the deterioration of USWR.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, (1) to (5) and (7) to (I41) are completely the same as the conventional device. The converting portion of 5) is tapered.

In the loaded line diode phase shifter configured as described above, the substrate substrate (2) and the diode (3) are soldered onto the ground conductor (1), and one electrode of the diode (3) is connected to the ground conductor (1). It is connected to the loading track using gold wire or gold ribbon. Next, a drive bias voltage is externally supplied from the bias pad αω and applied to the diode (3) via the main line and the loading line. At this time, by turning the drive bias voltage ON and OFF, the main line (7
) changes the susceptance value of the device line (8) as seen from
The transmission phase also changes.

This difference in transmission phase becomes the amount of phase shift.

Further, since there are DC cut capacitors (4) on the input side and the output side, the drive bias voltage does not affect other circuits connected to the phase shifter.

Here, if the DC cut capacitor (4) is wider than the main line width, the pad on which it is mounted will be even larger, and reflections due to impedance conversion will increase.

However, in an embodiment according to the present invention, the main line *(51
Since the connection part of the topad is tapered, the impedance can be gradually changed and reflections can occur.

In the above embodiment, a single-bit phase shifter has been described, but similar effects can be obtained with a multi-pit phase shifter configuration.

Further, although the above embodiment has been explained using a loaded line type phase shifter, the same effect can be obtained as a hybrid type phase shifter by replacing the phase delay circuit with a hybrid and a loaded line.

Furthermore, by making the phase delay circuit a switched line type, the same effect can be obtained as a switched line type phase shift circuit.

Further, in the above embodiment, a case has been described in which the conversion portion of the main line and the pad of the capacitor is tapered, but in this case, reflection cannot be suppressed unless the length of the taper is several wavelengths or more. However, if this conversion part is made into a step shape,
Matching is achieved at 174 wavelengths and reflection is observed. Figure 2 shows
It is a principle diagram of a step type conversion part. (5) is the main line with an impedance of Zl, f) 41 is a rectangular pad with an impedance of Z3, and (1) is a step-type converter with an impedance of Z2 and a length of 174 fi. Here, The value of Z2 that matches Zl and Z is determined by zz=,r)]11.

When the converting section is formed into a step shape in this manner, the same effect can be obtained in a form that is significantly smaller than the tapered type.

〔Effect of the invention〕

As described above, according to the present invention, the diode phase shifter D
The conversion part between the rectangular pad where the C-cut capacitor is mounted and the main line is tapered or stepped, so
Deterioration in VSWR due to impedance conversion can be reduced, and phase shift characteristics can be improved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a loaded line phase shifter according to an embodiment of the present invention, FIG. 2 is a principle diagram of a step type converter according to another embodiment of the present invention, and FIG. 3 is a perspective view of a loaded line phase shifter according to an embodiment of the present invention. FIG. 2 is a perspective view of a straight-line phase shifter. In the figure, (1) is the ground conductor, (2) is the substrate board,
(3) is a diode, (4) is a DC cut capacitor,
(5) is the main line, (6) is the tapered converter, (7) is the phase shifter main line, (8) is the loading line, (9) is the phase delay circuit, al is the bias pad, 011 is 174 A wavelength low impedance line, (threshold is a 174 wavelength high impedance line, ((3) is a bias circuit consisting of (1) and (2),
( ) 41 is a rectangular pad, and the symbol 41 is a step shape conversion part. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (2)

[Claims] (1) A substrate board and a diode soldered onto a ground conductor made of metal such as Kovar, and a phase delay circuit composed of a strip line on the substrate board, a main line, a bias circuit, and a diode on the main line. In a diode phase shifter comprising a DC cut capacitor mounted on a DC cut capacitor and equipped with means for applying a driving bias voltage to one electrode of a diode connected to the phase shift delay circuit, the DC cut capacitor having a dimension larger than the main line width is used. A diode phase shifter characterized by a pad provided for mounting a cut capacitor and a tapered conversion section of the main line. (2) A substrate board and a diode soldered onto a ground conductor made of metal such as Kovar, and a phase shift delay circuit and main line composed of a strip line on the substrate board, a bias circuit, and a bias circuit on the above main line. A diode phase shifter consisting of a DC-cut capacitor mounted in the circuit and equipped with means for applying a driving bias voltage to one electrode of the diode connected to the phase delay circuit, the DC-cut capacitor having a dimension larger than the main line width. A diode phase shifter characterized by having a pad provided for mounting a capacitor and a conversion section of the main line in a step shape.