JPH01256801A - Connection method for microstrip line - Google Patents

Abstract

PURPOSE:To easily compensate discontinuity of a microwave characteristic impedance by using a flexible connection conductor so as to connect the microstrip lines and adding an equivalent lumped constant capacitance to the tip of the said microstrip line connection. CONSTITUTION:The microstrip lines 28, 28' are arranged on a metallic case 29 with a gap 24. Then the microstrip line 28 has a microstrip conductor 22 and a capacitive stub 25 formed to one face of a dielectric base 21 with a ground conductor 23 formed on the other side. Furthermore, the microstrip line 28' has a microstrip conductor 22' and a capacitive stub 25' formed to one face of a dielectric base 21' with a ground conductor 23' formed on the other side. Then the microstrip lines 28, 28' are connected with a flexible conductor ribbon 26. Even if a large change takes place in the gap due to temperature change, the occurrence of break or crack is prevented.

Description

[Detailed Description of the Invention] [Summary] For example, a plurality of microwave circuits configured as MICs (microwave hybrid integrated circuits) are connected.

Regarding the connection method of the microwave strip line used when manufacturing parts with a certain function, it is necessary to prevent the connection part from breaking or cracking even if the ambient temperature changes, and to maintain the microwave characteristic impedance. In order to easily compensate for the discontinuity of When establishing and interconnecting
The microstrip lines are connected by a flexible connection conductor, and an equivalent lumped constant capacitance is added to the end portion of the connection side of the microstrip line.

[Industrial application field]

For example, it relates to a method for connecting microwave strip lines used when manufacturing a part with a certain function by connecting a plurality of MIC microwave circuits.

A microwave strip line is a modification of a parallel plate waveguide, and includes a ground conductor and a strip conductor, and an electric field is applied between the two conductors to propagate electromagnetic waves. This line has a planar structure and is suitable for making small, lightweight, and economical circuits, and is also compatible with semiconductor components, so it is often used as a basic line for MIC.

For example, when constructing a transmitter by placing MIC-format microwave circuits such as microwave band oscillators and microwave amplifiers in a metal case, the microstrip lines in these circuits must be connected to each other. It is necessary to prevent the connection portion from breaking or cracking even when the temperature changes, and to easily compensate for discontinuity in the microwave characteristic impedance.

[Conventional technology]

FIG. 7 is a configuration diagram of a conventional example, and FIG. 8 is a cross-sectional view taken along line A-A in FIG. 7. Hereinafter, the configuration in FIG. 7 will be explained with reference to FIG. 8.

A microstrip line 18 having a microstrip conductor 12 formed on one surface of a dielectric substrate 11 having a ground conductor 13 formed on the other surface, and a dielectric substrate having a ground conductor 13'' formed on the other surface. A microstrip line 18' having a microstrip conductor 12'' formed on one side at an angle of 11 degrees.

For example, it is assumed that the device is placed on the metal case 17 with a gap 14 of about 0.01 to Q, 1 mm.

Now, the two microstrip lines 18 and 18' are connected with a conductor ribbon, for example, the gold ribbon 16 with a thickness of about 20 μm, but the dielectric constant of the gap 14 is lower than that of the dielectric substrate 11°11°. Therefore, the microwave characteristic impedance becomes discontinuous in this part. Therefore, in order to compensate for this, a dielectric piece 15 is placed on top of the gold ribbon 16 and bonded.

[Problem to be solved by the invention]

Here, since the thermal expansion coefficients of the metal case 17 and the dielectric substrate 11.11'' are different, the gap 14 may change due to changes in ambient temperature.
changes in size. However, the conductor ribbon 16 connecting the two microstrip lines 18, 18' must be flat in order to place the dielectric piece 15 on it, and there is no room for expansion and contraction.

Therefore, there is a problem that the conductor ribbon may break or crack when the size of the gap changes.

The present invention prevents the connection from breaking even if the ambient temperature changes.

Another object is to prevent cracks from occurring and to easily compensate for discontinuity in microwave characteristic impedance.

[Means to solve problems]

FIG. 1 shows a block diagram of the principle of the present invention.

In the figure, 21.21' is a dielectric substrate, 23.23' is a ground conductor, and 22.22' is a mancross strip conductor.

Further, 28 and 28' are microstrip lines, 26 is a flexible connection conductor, and CIlC2 is an equivalent lumped constant capacitance added to the connection side tip of the microstrip line.

[Effect]

In the present invention, the conductor ribbon 26 is made to have flexure, and equivalent lumped constant capacitances C, C2 are added to the connecting end portions of the microstrip lines 28 and 28'.

That is, even if the size of the gap changes due to a change in temperature, the conductor ribbon is deflected, so the stress applied to the conductor ribbon is alleviated and breakage or cracking can be prevented.

In addition, by adding equivalent lumped constant capacitances C, C2 to the connecting end of the microstrip line 28.28°, it is possible to easily eliminate the discontinuity in the microwave characteristic impedance caused by the gap 24, as will be described later. can be compensated.

〔Example〕

2 is a block diagram of the embodiment, FIG. 3 is a sectional view taken along line BB' in FIG. 2, and FIG. 4 is an equivalent circuit diagram of FIG. 2. here,
The capacitive stub 25 is a component of C3 in FIG. 1, and the capacitive stub 25' is a component of C2 in FIG. The configuration shown in FIG. 2 will be explained below with reference to FIG.

First, as shown in Figures 2 and 3, place the ground conductor 2 on the other side.
A dielectric substrate 21 has a microstrip line 28 having a microstrip conductor 22 and a capacitive stub 25 formed on one side of the dielectric substrate 21 with a ground conductor 23 formed on the other side. A microstrip conductor 221 formed on one surface of the microstrip line 28g and a microstrip line 28g having a capacitive stub 251 are arranged on a metal case 29 with a gap 24 provided therebetween.

Since the microstrip lines 28 and 28° are connected by the flexible conductor ribbon 26, even if the gap size changes due to temperature changes.

Breaking or cracking is prevented.

Next, FIG. 4 is an equivalent circuit diagram of the connection part, where zo indicates the microwave characteristic impedance of the microstrip line 28.28', and C1 and C2 each indicate the capacitance of the capacitive stub 25.25''. , L indicates the inductance of the conductor ribbon 26.

Here, since the gap 24 is filled with air or the like, its dielectric constant is smaller than that of the dielectric substrate 2L 21°, and the microwave characteristic impedance of the transmission path consisting of the conductor ribbon 26 and the gap 24 is as follows. Microstrip line 2
It is larger than the microwave characteristic impedance Z0 of 8.28', and since the length is short, the phase change is small.
It can be equivalently expressed as an inductance. Also, the capacitive stubs 25,25' are designated C,,C,.

Now, when the microwave angular frequency is indicated by ω, C8#C2=
C, ω= (L-C)-””, ZO=(L/C)-”
The capacitive stub 25.2
By setting the length to 5°, it is possible to compensate for discontinuity in the microwave characteristic impedance caused by the gap 24.

FIG. 5 shows a block diagram of another embodiment. As shown in the figure, in addition to the conductor ribbon 26, flexible conductor wires 261 and 262 are used to connect the capacitive stubs 25 and 25'. This results in
Since the value of the inductance L shown in FIG. 4 can be changed, it is possible to finely compensate for the microwave characteristic impedance.

FIG. 6 is a configuration diagram of yet another embodiment, in which the connection end of a microstrip conductor 27°27'' having a capacitive stub at the connection end is formed to be shorter than the dielectric substrate 21.21°, and this connection By using stray capacitance caused by lines of electric force bulging out through the dielectric substrate from near the ends, that is, tip capacitance, the capacitive stub can be made smaller, and miniaturization becomes possible.

That is, by connecting the microstrip line with a connecting conductor with flexure and providing an equivalent lumped constant capacitor at the end of the connection side of the microstrip line, the connection part can be broken even if the ambient temperature changes. Alternatively, cracks do not occur, and discontinuity in microwave characteristic impedance can be easily compensated for.

〔Effect of the invention〕

As explained in detail above, according to the present invention, the connection part does not break or crack even if the ambient temperature changes, and discontinuities in the microwave characteristic impedance can be easily compensated for. be.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of the principle of the present invention, Fig. 2 is a configuration diagram of an embodiment, Fig. 3 is a sectional view taken along line BB' in Fig. 2, Fig. 4 is an equivalent circuit diagram of Fig. 2, and Fig. 4 is an equivalent circuit diagram of Fig. 2. Fig. 5 is a block diagram of another embodiment, Fig. 6 is a block diagram of yet another embodiment, Fig. 7 is a block diagram of a conventional example, and Fig. 8 is a sectional view taken along line A-A in Fig. 7. In the figure, 21 and 21° are dielectric substrates, 22.22'' is a microstrip conductor, 24 is a gap, 28.28' is a microstrip line, and C1 is an equivalent lumped constant capacitance. Principle of Invention Pro...77 Garden single figure R' Grass 4 days

Claims (1)

[Claims] Consists of a ground conductor (23, 23') formed on the back surface of a dielectric substrate (21, 21') and a microstrip conductor (22, 22') formed on the front surface. When connecting the microstrip lines (28, 28') with a gap (24), connect the microstrip lines with a flexible connecting conductor (26), and also Lumped constant capacitance (C_1, C_2) equivalent to the part
A method for connecting a microstrip line, characterized in that the following is added.