JPS6236323Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a diode phase shifter.

This type of phase shifter is generally a 3- to 5-bit phase shifter, which is made by cascading several stages of single-bit phase shifters that obtain a specific amount of phase shift, so we will focus on 3-bit phase shifters here. I will explain. Diodes used in phase shifters include PIN diodes and varactor diodes, but since the same can be said of both, the PIN diode will be explained here.

FIG. 1a shows an example of the structure of a 3-bit diode phase shifter constructed from a conventional triplate strip line. FIG. 1b is a sectional view along AA.

A ground conductor 2 is provided on one side of the dielectric lower substrate 1.
The metal case 3 is coated with metal and is arranged to make good electrical contact with the metal case 3. The entire other surface of the dielectric lower substrate 1 is a dielectric plane. On both sides of the dielectric intermediate substrate 4 are a main line 5, a 3dB hybrid coupler 6 composed of coupled lines, a DC block capacitor 7 for separating the DC bias from the external circuit, and a line for the reflected wave phase conversion circuit. 8 and 1/4 used for bias circuit
A low impedance line 9 having a wavelength length and a high impedance line 10 having a length of 1/4 wavelength used for a bias circuit are formed using a photoetching method. In addition, the tip of the line 8 for the reflected wave phase conversion circuit is connected via a gold wire (not shown) or the like.
The bias supply terminal 12 is connected to the PIN diode 11, and the bias supply terminal 12 is connected to a bias terminal 13 mounted on the metal case 3 via a suitable metal wire (not shown).

One surface of the dielectric upper layer substrate 14 is coated with metal that will become the ground conductor 2, and the metal case upper lid 1
5, and the side facing the other dielectric intermediate layer substrate 4 is a dielectric plane.

Further, 16 is a plug seat for connecting to an external circuit. Note that in FIG. 1a and the structural explanatory diagrams shown below, the dielectric middle layer substrate 4, dielectric upper layer substrate 14, and metal case top cover 15 are removed and shown at the top for ease of understanding.

FIG. 2 is a diagram for explaining the operation of the phase shifter shown in FIG. 1a. For simplicity, a single-bit phase shifter is shown. Radio waves incident from the main line 5 on the input side pass through a DC blocking capacitor 7. This DC blocking capacitor 7 serves to separate the DC bias supplied to the PIN diode 11 via the bias circuit 17 from an external circuit.

Next, the radio wave that has passed through the DC blocking capacitor 7 enters a 3 dB hybrid coupler 6 made up of a coupled line, and the power appears at terminals T ₁ and T ₂ as being equally distributed. The reflected wave phase conversion circuit 18 connected to these terminals T ₁ and T ₂ includes a PIN diode 11
It is designed so that the phase change of the reflected wave obtained by switching the polarity of the DC bias applied to the waveform becomes a predetermined value.

The radio wave reflected by the reflected wave phase conversion circuit 18 is
Passes through the DC block capacitor 7 on the output side,
The reflected wave appears on the main line 5 on the output side, but when the polarity of the bias applied to the PIN diode 11 is switched, the reflected wave phase converter circuit 18 as described above.
is designed, the phase of the output radio wave undergoes a predetermined phase change, forming a diode phase shifter.

In a diode phase shifter constructed with this type of triplate strip line, the metal case width W, which is orthogonal to the radio wave propagation direction, is designed to be such a width that the waveguide mode radio wave propagation is interrupted. There is.

On the other hand, the wider the width of the low impedance line 9 formed on both sides of the dielectric intermediate substrate 4, the better the characteristics of the bias circuit 17 will be. Therefore, the bias circuit 17 occupies a large area on both sides of the dielectric intermediate substrate 4 inside the diode phase shifter.

As described above, in the conventional phase shifter of this kind, the width W of the metal case is limited and the area of the low impedance line 9 needs to be large. Since the phase shifter was arranged so as to match the length direction of the device, the length of the phase shifter became long, resulting in a large size.

That is, the conventional method of arranging the low impedance line 9 has the disadvantage that the phase shifter becomes large.

The idea is to provide low impedance lines 9 with a length of 1/4 wavelength at opposing positions on both sides of the intermediate layer dielectric substrate 4, and the purpose is to obtain a small and lightweight diode phase shifter. .

FIG. 3a shows an embodiment of a 3-bit diode phase shifter constructed from a triplate strip line according to this invention.

FIG. 3b shows only the single-bit phase shifter of FIG. 3a.

Further, FIG. 3c is a sectional view taken along line AA in FIG. 3b. A low impedance line 9 having a length of 1/4 wavelength used for the bias circuit is connected to the intermediate layer dielectric substrate 4.
are formed at opposite positions on both sides.

Therefore, the area occupied by the bias circuit 17 on the substrate is reduced, and in the phase shifter shown in FIG. 3a, the phase shifter can be shortened and miniaturized.

Although the case of a 3-bit phase shifter has been described above, this invention is not limited to this, and may be used in other types of phase shifters having any number of bits.

As described above, the diode phase shifter according to this invention can be made compact and lightweight.

[Brief explanation of the drawing]

Figure 1a is a perspective view showing the structure of a 3-bit diode phase shifter constructed with a conventional triplate strip line, Figure 1b is a sectional view along its AA, and Figure 2 is a diagram showing the structure of a conventional triplate strip line. Figure 3a is a perspective view showing the structure of a 3-bit diode phase shifter constructed from a triplate strip line according to this invention. Figure b is Figure 3a
A perspective view showing the structure of only the single-bit diode phase shifter is shown, and FIG. 3c is a cross-sectional view along line AA. In the figure, 1 is a dielectric lower layer board, 2 is a ground conductor, 3 is a metal case, 4 is a dielectric middle layer board, 5 is a main line,
6 is a 3dB hybrid coupler composed of coupled lines, 7 is a DC cut capacitor, 8 is a line for reflected wave phase conversion circuit, 9 is a low impedance line,
10 is a high impedance line, 11 is a PIN diode, 12 is a bias supply terminal, 13 is a bias terminal, 14 is a dielectric upper layer substrate, 15 is a metal case top cover, 16 is a plug seat, 17 is a bias circuit, 18
is a reflected wave phase conversion circuit. It should be noted that the same or corresponding parts in the figures are indicated by the same reference numerals.

Claims (1)

[Scope of utility model registration request] Two dielectric substrates, one side of which is a ground conductor,
A diode transfer device is placed between these and consists of an intermediate dielectric substrate with line conductors formed on both sides, a PIN diode, and a metal case that shields them from the outside, and has means for applying a DC bias to the PIN diode. In a phase converter, a bias circuit consisting of a high impedance line with a length of 1/4 wavelength and a low impedance line with a length of 1/4 wavelength formed on both sides of the intermediate layer dielectric substrate, the low impedance line is formed on both sides of the intermediate layer dielectric substrate. A diode phase shifter characterized in that lines are formed at opposing positions on both sides of an intermediate layer dielectric substrate.