JPH07202519A - Micro wave circuit - Google Patents

Abstract

PURPOSE:To miniaturize a micro wave circuit board and to extend the path of a signal by cutting a pattern on the surface of the board to change the operation of the circuit. CONSTITUTION:A normal micro wave circuit is patterned on the surface or a multilayered dielectric substrate, and patterns are formed between layers in the same manner and are connected to the pattern in the surface layer by through holes 4. With respect to adjustment of the circuit, the pattern in the surface layer is cut by a laser, so the path of an RF signal passes a line arranged between layers through the through hole 4 and is returned to the surface layer through another through hole 4. Thus, the path of the signal is changed to change the inductance of the micro wave circuit. A ground is arranged between layers to take countermeasures against inter-line interference and noise.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave circuit having a microwave impedance adjusting circuit. In particular, it relates to a trimmable multilayer stripline structure.

[0002]

2. Description of the Related Art As shown in FIG. 4, impedance adjustment of a conventional microwave circuit is a stripline 2 formed in a U shape on a single-layer dielectric substrate 1 by using a thick film forming technique.
And had a ladder-like strip line connected to the line so as to short the line inside this line. In the impedance adjustment, while monitoring the relevant characteristics, a portion of the ladder-shaped stripline that is close to the U-shape is selectively irradiated by the laser beam.
The operation of the circuit is changed by thermally cutting in the B and A'-B 'directions. (Japanese Patent Laid-Open No. 58-18768)

[0003]

In this impedance adjusting circuit configuration of the microwave circuit, since the ladder-shaped strip line is formed in a plane, the area of the circuit pattern becomes large, and it is difficult to reduce the size. It was

[0004]

A microwave circuit according to the present invention is a strip line formed on the surface of a multilayer or single-layer dielectric substrate, a through hole provided on the strip line, and a dielectric connected by this through hole. A strip line between the lower layer of the body substrate or the interlayer is provided. The impedance adjustment increases the inductance by selectively cutting the strip line on the upper surface of the substrate while monitoring the related characteristics, thereby changing the operation of the circuit.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a partial sketch of a circuit configuration for impedance adjustment of a microwave circuit according to an embodiment of the present invention.

In FIG. 1, a strip line 2 is formed of a Cu 50 μm film on the upper surface of a 20 × 14 mm dielectric substrate 1 made of, for example, 4 layers of alumina having a thickness of 0.6 mm. Board 3
A through hole 4 of, for example, 200 μmφ connected to the through hole 4 is formed in the lower dielectric substrate 3.
A strip line 2 having the same width as the strip line 2 formed on the dielectric substrate 1 for connecting the two is formed.

The lower surface of the lower dielectric substrate 3 is a ground electric plate surface 7.
For this purpose, a ground electrode made of, for example, a CuNi alloy having a thickness of 0.5 mm is formed.

When adjusting the impedance, only the upper surface of the strip line 2 formed on the surface of the dielectric substrate 1 is monitored while monitoring the impedance such as S ₁₁ and S ₂₂ at a desired frequency and related characteristics such as output power and gain. A, for example, ab with a length of 1 mm is connected with a laser beam A
By cutting in the -B direction, the path of the strip line 2 becomes like aa'b'b passing through the upper and lower surfaces of the dielectric substrate 1, and the line of the strip line 2 becomes longer, which changes the operation of the circuit. Let (A'b 'can be the underside of the substrate avoiding any interlayer or ground electrode pattern.) FIG. 2 shows a configuration diagram of the second embodiment of the present invention.

The dielectric substrates 1 and 3 are the same as those in the first embodiment, and the strip line 2 formed on the upper surface of the dielectric substrate 1 is arranged as shown in FIG. 2, and for example, the width is 0.5 mm and the length is 1 m.
Through-holes 4 for connecting to the lower dielectric substrate 3 are formed at both ends of the strip line 2 extending in a branch shape of m. A strip line 2 is formed to connect one through hole 4 to the other through hole 4 '.

When adjusting the impedance, the stripline 2 connected to the branch-shaped stripline 2 on the upper surface of the upper substrate is cut by a laser beam or the like while monitoring the impedance and related characteristics, so that the stripline It changes the electrical length and changes the operation of the circuit.

FIG. 3 shows a third embodiment of the present invention. The multilayer dielectric substrate 1 is the same as that of the first embodiment, except that the through holes 4 and the interlayer strip lines 5 are avoided between layers, and the ground electric plate pattern 6 and the through holes 4 ″ on the lower surface of the dielectric substrate 1 are provided.
The substrate upper surface stripline 2 and the interlayer stripline 5 having the interlayer ground electrode 7 connected by are similar to those of the first embodiment, and the impedance adjustment adjusts the substrate upper surface stripline 2 of the dielectric substrate 1 while monitoring the related characteristics. To change the operation of the circuit. Compared to the first embodiment, the third embodiment has a circuit-stable circuit by arranging the ground electrode pattern 7 between layers. For example, the presence or absence of the ground electrode pattern layer 7 reduces coupling by 10 dB or more.

[0013]

As described above, according to the present invention, since the ladder-shaped strip line is formed in the vertical direction by forming the substrate in multiple layers, the substrate area can be reduced and the substrate can be miniaturized.

When the ladder-like strip line occupies 30% of the circuit board, the reduction rate of the board is determined by moving the pattern, which is planarly spread on the board-like surface, to the interlayer or lower layer of the multilayer board. It is possible to reduce the part ratio of 30% by 80% and the substrate area by 24%. Therefore, the size of the board and the case that wraps the board are 18 × 1
When the case of 2 × 4 mm is used as the original shape, there is an effect of reducing the surface area by 20% and reducing the cost by 3%.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a configuration diagram of a third embodiment of the present invention.

FIG. 4 is a block diagram of a conventional example

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Dielectric multilayer board 2 ... Board stripline 3 ... Lower dielectric board 4 ... Through hole 5 ... Interlayer stripline 6 ... Substrate bottom surface grounding electric plate 7 ... Interlayer ground electrode 4 ″ ... Ground electrode connecting through hole

Claims (2)

[Claims] 1. A plurality of through hole conductors for connecting a wiring pattern formed on the uppermost layer surface of a dielectric substrate having a plurality of layer structures and a strip line formed on a lower layer dielectric substrate. A microwave circuit comprising a conductor having parallel branches and an electronic circuit connected to the conductor, wherein the operation of the circuit is changed by cutting a part of a wiring pattern formed on the uppermost layer surface. 2. The wiring pattern formed on the uppermost layer surface and a plurality of independent strip lines formed on the lower dielectric substrate are connected by a through-hole conductor from the tip of the strip line. 1. The microwave circuit according to 1.