JPH0352002Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a diode phase shifter that can digitally vary the transmission phase amount, and is particularly applicable to radar and ECM.
The present invention relates to a diode phase shifter that is suitable for application to phased arrays used in other applications.

[Conventional technology]

As this type of diode phase shifter, those with the structure shown in Figs. .19, 1983
2013, pages 64 to 74.

This diode phase shifter will be explained below with reference to FIGS. 2 to 4.

FIG. 2 is a perspective view showing the overall configuration of a conventional diode phase shifter, and FIG. 3 is a plan view showing an enlarged part of the planar circuit pattern of the phase shifter shown in FIG. , FIG. 4 is a sectional view taken along line A--A in FIG. 3.

In these figures, a plate 2 to which terminals 4a to 4d are attached is erected at one end of a metal plate 2, and a dielectric substrate 8 is fixed onto the metal plate 2. A planar circuit pattern 10 of a metal conductor having a shape as shown in the figure is formed on this dielectric substrate 8 using a thin film production technique. Planar circuit pattern 1
0 is a loaded line type phase shift circuit 12A, 12B including the line 11, a reflection type phase shift circuit 14A, 14B including the line 11, and connection terminals 16a to 16d.
including phase shift circuits 12A, 12B, 14A, 14
Bias circuits 18a to 18d each connected to B
The bias circuits 18a to 18d are individually provided with low pass filters 20a to 20d, and high frequency input/output lines 22a and 22b. Further, each phase shift circuit 12 is provided on the dielectric substrate 8.
At the positions corresponding to A, 12B, 14A, 14B
PIN diode elements 26a ₁ , 26a ₂ , 26b ₁ , 2
6b ₂ , 26c ₁ , 26c ₂ , 26d ₁ and 26d ₂ are provided.

As shown in FIG. 3, the means for grounding this PIN diode 26 is as follows, without using a so-called ground plane.
A 1/4 wavelength open stub 50 is used to ground the high frequency. The transmission line 11 has a common ground potential without using a capacitor, and is grounded to the metal plate 2 through a high frequency cable 52. Further, the 1/4 wavelength open stub 50 is connected to a bias circuit 56 having a high frequency choke 54. Bias circuit 5
6 is provided with a bias end 58. One end of a PIN diode 26 is fixed to the end of the 1/4 wavelength open stub 50, and the other end of the PIN diode 26 is connected to one end of the phase shift circuit 12 with a metal wire 60. be.

The operation of the circuit configured in this way will be explained.
When a DC bias is applied to the bias end 58,
Direct current flows through the diode 26 via the bias circuit 54.
join. Then, the diode 26 becomes conductive, and
A direct current flows through the metal plate 2, the high frequency choke 52, the phase shift circuit 12, the diode 26, the 1/4 wavelength open stub 50, and the bias circuit 56. This phase shift circuit 12 is configured to obtain a desired amount of phase shift.

Therefore, the high frequency wave propagating through the line 11 has a constant phase amount.

Note that the open stub is not limited to 1/4 wavelength;
(1+2n) wavelengths (where n=0, 1, 2, 3,
...) are also used. Note that a certain amount of space is required except when n=0. In short, for a 1/4 (1+2n) wavelength open stub,
It is best to use this as the ground plane because its input impedance is the smallest compared to other lengths, and the frequency characteristics are also the best.

[Problem that the invention attempts to solve]

In such conventional diode phase shifters, if the amount of phase shift deviates from the set value, the diode is replaced (change of junction capacitance), but it is also necessary to redo the wire bonding of the diode (change of inductance). It is being done. However, all of these methods have the drawbacks of increasing man-hours, lowering reliability, and being unsuitable for mass production.

[Purpose of invention]

An object of the present invention is to provide a diode phase shifter that can obtain a desired phase shift amount while being set in a measuring instrument during phase shift adjustment and inspection.

[Means for solving problems]

The present invention provides a correction pattern on the high-frequency grounding stub to facilitate correction of phase shift errors. In other words, the present invention forms a predetermined number of phase shift circuits with a metal conductor pattern on a dielectric substrate to provide a constant amount of phase change, and separates and connects the phase shift circuits to a ground point to open up to 1/4 wavelength. A diode phase shifter comprising a diode attached to a high frequency grounding means formed of a metal pattern consisting of a stub, and a bias circuit capable of applying a bias to the diode, wherein a correction pattern is provided at the open end of the stub, The present invention is characterized in that the inductance of the diode can be equivalently increased or decreased by separating the correction pattern.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 shows an embodiment of the present invention.

In the figure, the PIN diode 26 is grounded at high frequency by a 1/4 wavelength (1/4λg) open stub 50. The transmission line 11 uses a common ground potential without using a capacitor, and connects it to the high frequency cable 5.
2 and is grounded to the metal plate 8.

A correction pattern 100 is provided at the open end of this 1/4 wavelength open stub 50. This correction pattern 100 is provided at the open end of a 1/4λg open stub, and has a narrow band pattern, and each band pattern is connected by a wire. By disconnecting this wire, the inductance of the PIN diode 26 can be changed. for example,
To obtain a phase shift of 180° (note that Figure 1 is not a 180° phase shift circuit), the junction capacitance of the PIN diode 26 is C', and the inductance of the bonding wire is L, then L/C=(1- ω ² CL) = Z _O ² ...(1) However) Z _O : Must satisfy the characteristic impedance of the transmission line. However, due to variations in C of the diode and L of the bonding wire, it often does not match the design value of equation (1). Therefore, the wire of this correction pattern 100 is separated and the value of 1/4λg is changed to obtain the inductance of the diode to obtain the desired amount of phase shift. That is, inductance L' is added depending on the wavelength (λg') of the correction pattern 100. This inductance L' is L'=Zt/ωtan2πλg'/λg...(2) However) Zt: Characteristic impedance of the stub In addition, the phase shift can be corrected in the direction of decreasing L'(λg'). Determine C and L in advance,
The desired amount of phase shift can be obtained by adjusting the amount of phase shift (allowing for variations in C and L) and by "peeling off" the bonding wire while it is set in the measuring instrument during inspection. Further, the 1/4 wavelength open stub 50 includes a bias circuit 56 having a high frequency choke 54.
is connected. This bias circuit 56 includes
A bias end 58 is provided. In addition, a PIN diode 26 is connected to the end of the 1/4 wavelength open stub 50.
One end of is fixed, and its PIN diode 2
The other end of 6 is connected to the phase shift circuit 1 with a metal wire 60.
It is connected to one end of 2.

The operation of the embodiment configured in this way will be explained. When a DC bias is applied to the bias end 58, the DC is applied to the diode 26 via the bias circuit 54. Then, the diode 26 becomes conductive, and a direct current flows through the metal plate 2, the high-frequency chain 52,
It flows through the phase shift circuit 12, the diode 26, the 1/4 wavelength open stub 50, and the bias circuit 56. This phase shift circuit 12 is configured to obtain a desired amount of phase shift.

[Effect of idea]

As explained above, according to the present invention, the inductance of the diode can be corrected by providing a correction pattern and reducing the minute inductance L'(λg') (stripping off the bonding). The amount of phase shift can be adjusted while inspecting the set.

Further, according to the present invention, since the phase shifter can be adjusted while being set in the measuring instrument, special skills for inductance adjustment are not required.

Further, according to the present invention, the inductance of the diode can be finely adjusted because the adjustment is made by cutting off the strip pattern of the correction pattern.

Moreover, since the present invention has a correction pattern for adjusting the inductance of the diode,
It is also possible to improve the frequency characteristics of the amount of phase shift.

Further, according to the present invention, it can be effectively used regardless of the circuit type (low date line type, reflective type).

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is an overall configuration diagram of a conventional diode phase shifter, and FIG. 3 is a partially enlarged view of the planar circuit pattern of the phase shifter in FIG.
FIG. 4 is a sectional view taken along the line AA in FIG. 3. 11...Transmission line, 26...Diode, 50...
...1/4 wavelength open stub, 100...correction pattern.

Claims (1)

[Scope of utility model registration request] A predetermined number of phase shift circuits with a certain amount of phase change are formed using a pattern of metal conductors on a dielectric substrate, and the phase shift circuits are connected to and separated from a ground point by a metal pattern consisting of 1/4 wavelength open stubs. In a diode phase shifter that includes a diode attached to the high frequency grounding means to be formed and a bias circuit capable of applying a bypass to the diode, a correction pattern is provided at the open end of the stub, and the correction pattern is separated. A diode phase shifter characterized in that the inductance of the diode is increased or decreased equivalently.