JPH01293001A - Connecting structure for micro-strip line - Google Patents

Abstract

PURPOSE:To prevent breakage of the connecting part of micro-strip lines even when the ambient temperature changes by connecting a 1st micro-strip conductor to a cepacitive stab with the flexible connecting conductor and the capacitive stab to a 2nd micro-strip conductor with an inductive line having the same inductance. CONSTITUTION:At the time of connecting the 1st and 2nd micro-strip lines 3 and 3' to each other through a space 16, the capacitive stab C is formed at the connecting end section of a 2nd inductive base plate 33 with a clearance against the 2nd micro-strip conductor 34. Then the 1st micro-strip conductor 32 is connected to the capacitive stab C with a 1st connecting conductor L1 and the capacitive stab C is connected to the 2nd micro-strip conductor 34 with a 2nd connecting conductor L2 which is sufficiently flexible or the 3rd micro-strip conductor L2 having a narrower width than the 2nd micro-strip conductor 34 has. Therefore, the connecting parts do not break or no crack is produced in the connecting part even when the ambient temperature changes.

Description

[Detailed Description of the Invention] [Summary] For example, microwave technology is used when manufacturing a part with a certain function by connecting multiple microwave circuits that have been converted into old C (microwave hybrid integrated circuits). Regarding the connection structure of a strip line, the connection part is prevented from breaking or cracking even if the ambient temperature changes, and even if a capacitive stub is not formed at the connection end of one dielectric substrate.

The purpose is to compensate for the discontinuity of the microwave characteristic impedance of the connection part, and the first and second
first and second dielectric substrates having a ground conductor formed thereon and disposed in the same metal case with a gap therebetween; and first and second dielectric substrates formed on the surfaces of the first and second dielectric substrates. When interconnecting the first and second microstrip lines configured with the first microstrip conductor, a capacitive stub is formed at the connection end on the surface of the second dielectric substrate, and A first flexible connecting conductor connects the microstrip conductor and the capacitive stub.

The capacitive stub and the second microstrip conductor are connected by an inductive line having the same inductance as the first connecting conductor, and the capacitance of the capacitive stub is made C9 the inductance of the inductive line, and the transmission frequency is ω/2π, the impedance of the first and second microstrip lines is 20
When ω-(L・C)-””, ZO=(L/C)
Create a structure that looks like this.

[Industrial application field]

For example, it relates to a connection structure for microwave strip lines used when connecting a plurality of MIC microwave circuits to produce parts with eight functions.

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, M of microwave oscillators, microwave amplifiers, etc.
When constructing a transmitter by placing an IC microwave circuit in a metal case, the microstrip lines in these circuits must be connected to each other, but even if the ambient temperature changes, the connections will break.

Alternatively, it is possible to prevent cracks from occurring and to compensate for the discontinuity of the microwave characteristic impedance of the connection part even if a capacitive stub is not formed at the connection end of one dielectric substrate. is necessary.

[Conventional technology]

FIG. 4 is a block diagram of a conventional example, FIG. 4(a) is a perspective view of the conventional example, and FIG. 4(b) is a sectional view taken along the line AA' in FIG. 4(a). The configuration of FIG. 4(a) will be described below with reference to FIG. 4(bl).

In the figure, a ground conductor (not shown) is formed on the back side,
A dielectric substrate 12° 14 is disposed on the metal case 11 with a gap 16 of 1, for example, O6 old to 0.11 imperial throne, and
When connecting the microstrip conductor 13.15 formed on the surface of the dielectric substrate to the microstrip line 1,1° with a conductor ribbon, for example, a gold ribbon 18 with a thickness of about 20 μm, there is a gap. Dielectric substrate 1 has a dielectric constant of 16.
Since the dielectric constant is lower than the dielectric constant of 2.14, the microwave characteristic impedance becomes discontinuous in this part.

Therefore, in order to compensate for this discontinuity, a dielectric piece 17 is placed on top of the gold ribbon 18 and bonded.

FIG. 5 shows a configuration diagram of another conventional example. As shown in the figure, a ground conductor (not shown) is formed on the back side.

A microstrip line 2, 2' is constituted by a dielectric substrate 2L 24 placed on the same metal case 11 with a gap 16 in between, and a microstrip conductor 22.25 formed on the surface of the dielectric substrate. There is.

Here, the capacitive stub 23.2G is connected to the above microstrip 1.22.25 on the dielectric substrate 21°24.
These capacitive stubs are connected by a flexible conductor ribbon 27 to compensate for the discontinuity of the microwave characteristic impedance in the gap 16.

[Problem to be solved by the invention]

Here, in the case of FIG. 4, since the thermal expansion coefficients of the metal case 11 and the dielectric substrates 12 and 14 are different, the size of the gap 16 changes due to a change in ambient temperature. However, the conductor ribbon 18 that connects the two microstrip conductors 13 and 15 must be flat in order to place the dielectric piece 17 on it, and there is no room for expansion and contraction. Therefore, there is a problem that when the size of the gap changes, the four-body ribbon may break or crack.

Furthermore, if the microstrip conductor is connected with a flexible conductor ribbon 27 as shown in Fig. 5, even if the size of the gap 16 changes due to a change in ambient temperature, this conductor ribbon will break or crack. Never. However, it is necessary to make the characteristic values of the capacitive stubs 23.2G almost equal.
Since capacitive stubs have frequency characteristics, general-purpose old Cs that operate over a wide band do not use them. ) and the microstrip conductor is impossible.

[Means to solve problems]

FIG. 1 shows a principle block diagram (equivalent circuit) of the present invention.

In the figure, C is a capacitive stub formed at the connection end of the surface of the second dielectric substrate, and Ll is a flexible first capacitive stub that connects the first microstris conductor 32 and the capacitive stub 6.
is the connecting conductor.

Furthermore, L2 is an inductive line that connects the capacitive stub and the second microstrip conductor and has the same inductance as the first connecting conductor, and the capacitance of the capacitive stub is connected to the inductive line C9. The inductance of Ll−L2・
When L, the transmission frequency is ω/2π, and the impedance of the first and second microstrip lines is 20,
ω=(L −C)−””, Zo□(L/c)I/!
Make it so that

[Effect]

The present invention provides a first microstrip line 3 composed of a first dielectric substrate 31 and a first microstrip conductor 32 formed at a connecting end on the surface of this substrate, and a second dielectric substrate 33. When connecting the second microstrip line 31 formed by the second microstrip conductor 34 formed on the surface of this substrate through the gap 16, a capacitor is added to the connection end of the second dielectric substrate 33. The magnetic stub Cfc is formed with a gap provided between it and the second microstrip conductor 34.

Then, the first microstrip conductor 32 and the capacitive stub C are connected to the first contact having sufficient deflection using a four-body L1, and the capacitive stub and the second microstrip conductor 34 are connected to each other with sufficient deflection. Second contact with deflection>'A R body L2+
Alternatively, a third microstrip conductor L2 having a width narrower than that of the second microstrip conductor is used for connection.

This prevents the connection from breaking or cracking even if the ambient temperature changes, and even if a capacitive stub is not formed at the connection end of one microstrip line, as will be described later. Can perform discontinuous compensation for microwave characteristic impedance.

[Embodiment] FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a block diagram of another embodiment of the present invention.

Here, the conductor ribbons 511 and 521 are integral with the flexible first and second contacts M"J, L2, the microstrip conductor 5211 is a component of the third microstrip conductor L2, and the capacitive stub. 61 is a component of the capacitive stub C. Also, the same reference numerals indicate the same objects throughout the figures.

First, the microstrip line 3 in FIG. 2 is composed of a dielectric substrate 31 and a microstrip conductor 32 formed on it, and the microstrip line 3 is composed of a dielectric substrate 33 and a microstrip conductor 32 formed on it. It is composed of a capacitive stub 61 and a microstrip conductor 34,
The capacitive stub 61 and the microstrip conductor 34 are close to each other with a gap 62 interposed therebetween.

The microstrip lines 3 and 39 are arranged on the metal case 11 with a gap 16 in between, and for example, conductor ribbons 511 and 521 having the same width are integrally formed.
microstrip conductor 32 and capacitive stub 61. Capacitive stub 61 and microstrip conductor 34
and are each bridged.

Here, the portion where the conductor ribbon 511 crosses the gap 16 is
Since the gap is filled with air whose dielectric constant is smaller than the dielectric constant of the dielectric substrate 31, 33, MM is measured isometrically as shown in Figure 1.
``J-type impedance (inductance) L. Also, since the space between the dielectric substrate 33 and the conductor ribbon 521 is filled with air in the portion where the conductor ribbon 521 crosses the gap 62, it is the same as above. isometrically 2M
It can be expressed as m-type impedance (inductance) L2.

Further, the capacitive stub 61 can be equivalently represented by capacitive impedance (capacitance) C.

Then, the dimensions of the capacitive stub 61, the dimensions of the gap 62, and the widths of the conductor ribbons 511 and 521 are appropriately selected.
L, =L, ω=(L,C)-1”, zo, (
If L/C)'' is established, only the resistance equal to Zo will be present, and the discontinuity of the microwave characteristic impedance due to the gap 16 can be compensated for. Here, ω represents the angular frequency +20 represents the characteristic impedance of the microstrip lines 3 and 3'.

Incidentally, since the equivalent circuit of FIG. 1 does not include a phase shifter, FIG. 2 is not strictly shown, but it is sufficiently meaningful for qualitative explanation.

Next, in FIG. 3, the gap 62 between the capacitive stub 16 and the microstrip conductor 34 in FIG. 2 is replaced with a microstrip conductor 521° narrower in width than the microstrip conductor 34.

Since this can also be equivalently expressed by inductive impedance (inductance) tz, it is expressed by the equivalent circuit shown in FIG.

In other words, the connection will break even if the ambient temperature changes.

Alternatively, cracks do not occur, and a capacitive stub is not formed at the connection end of one microstrip line (although discontinuity compensation for the microwave characteristic impedance of the connection part can be performed).

〔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 a capacitive stub is provided at the connection end of one microstrip line. There is an effect that discontinuity compensation of the microwave characteristic impedance of the connecting portion can be performed even if the connecting portion is not formed.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram (equivalent circuit) of the present invention, Fig. 2 is a block diagram of an embodiment of the present invention, Fig. 3 is a block diagram of another embodiment of the present invention, and Fig. 4 is a block diagram of a conventional example. Block diagram: FIG. 5 shows a block diagram of another conventional example. In the figure, 3 is the first microstrip line, and 3° is the second microstrip line!・Rip line, 11 is a metal case, 16 is a gap, 31 and 33 are dielectric substrates, 32 is a first microstrip conductor, 34 is a second microstrip conductor, C is a capacitive stub, Ll is the first 1 connection conductor, L2 is the 2nd connection conductor, ? +4 +Aiki/Igo August Nojiri Fukuchi,,,yM (equal convex circuit) 1st
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Claims (1)

[Claims] First and second dielectric substrates (31, 33) and first and second microstrip conductors (32, 34) formed on the surfaces of the first and second dielectric substrates.
and the second microstrip line (3, 3'), a capacitive stub (C
), connect the first microstrip conductor and the capacitive stub with a flexible first connection conductor (L_1), and connect the capacitive stub and the second microstrip conductor with the first It is connected with an inductive line (L_2) having the same inductance as the connecting conductor (L_1), the capacitance of the capacitive stub is C, and the inductance of the inductive line is L_1=L_2.
=L, when the transmission frequency is ω/2π, and the impedance of the first and second microstrip lines is Z_0, ω=(L・C)^-^1^/^2, Z_0=(L/C)
A microstrip line connection structure characterized in that it is ^1^/^2.