JPH09321505A - Microwave circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deterioration in the characteristic due to inductance in the case of connecting distributed constant lines being components of the microwave circuit. SOLUTION: A ground conductor 12, a dielectric board 14 and a conductor line 36 are laminated in a chip 28 to form a microstrip line 18. Similarly a ground conductor 13, a dielectric board 16 and a conductor line 38 are laminated in a chip 30 to form a microstrip line 20. The conductor lines 36, 38 are formed rectangular and the chips 28, 30 are positioned by the use of a backing metallic plate 10 so that the lines are arranged on a line. A line region 40 of the conductor line 36 and a line region 42 of the conductor line 38 are connected by an overlay dielectric 22 and a coupling strip 24 is provided onto the dielectric 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to microwave circuits, and more particularly to coupling between distributed constant lines when a plurality of chips having distributed constant lines are integrated.

[0002]

2. Description of the Related Art A microwave circuit is a so-called distributed constant circuit, and a distributed constant line is used to guide a microwave signal. Here, as the distributed constant line, a line formed of a conductor line, a dielectric substrate, and a ground conductor is targeted. In this specification, a microwave circuit configured by forming a distributed constant line having such a configuration on one dielectric substrate is referred to as a chip. Conventionally, when a plurality of chips are integrated to form a circuit, coupling between distributed constant lines has been performed by bonding wires, ribbons, etc. (Reference I; microwave semiconductor circuit, p. 13).
9 Figure 6.13, published by Nikkan Kogyo Shimbun in 1993).

The perspective view of FIG. 4 shows the conventional coupling between the distributed constant lines of the first chip 28 and the second chip 30, respectively. The first chip 28 has a first distributed constant line 32, and the first distributed constant line 3
2 includes a first ground conductor 12, a first dielectric substrate 14, and a first conductor line 32, which are sequentially laminated. The second chip 30 has a second distributed constant line 34, and the second distributed constant line 34 includes the second ground conductor 13, the second dielectric substrate 16, and the second conductor line 38 sequentially laminated. Is configured. In order to simplify the drawing, the first chip 28 and the second chip 30 in FIG. 4 are composed of only distributed constant lines, and other microwave circuit elements and the like normally provided are omitted. ing. Therefore, each of the first chip 28 and the second chip 30 has a first
The distributed constant line 32 and the second distributed constant line 34 themselves. The coupling between the first distributed constant line 32 and the second distributed constant line 34 is performed by the first conductor line 36 and the second conductor line 3
The wire 26 connecting the first ground conductor 12 and the second ground
This is performed by using the base metal plate 10 that connects the ground conductor 13.

[0004]

However, as described with reference to FIG. 4, when the chips 28 and 30 are provided on the base metal plate 10, the dimensional accuracy of the size of each chip (mainly, Depending on the dimensional accuracy of the size of the dielectric substrate) and the assembly accuracy (accuracy related to alignment and processing), a gap of at least about 0.1 to 0.2 mm is opened between the chips. Therefore, for example, when the wire 26 is bonded to each of the first and second conductor lines 36 and 38 and the two are coupled to each other, at least 0.
Inductance of about 1 to 0.2 nH is the first and second
It will be inserted in series between the conductor lines 36 and 38.

Therefore, these first and second conductor lines 3
An impedance mismatch between 6 and 38 (ie, an impedance mismatch between the microwave circuits configured on each chip 28 and 30),
Microwave circuit characteristics (gain and VSWR (voltage st
anding wave ratio)) was deteriorated. The higher the operating frequency, the less satisfactory the characteristics were.

Therefore, conventionally, it has been desired to develop a microwave circuit having a structure in which distributed constant lines are coupled while maintaining good characteristics.

[0007]

According to the microwave circuit of the present invention, two chips each having a distributed constant line composed of a conductor line, a dielectric substrate and a ground conductor are provided on a base metal plate. A microwave circuit formed by combining the ground conductors with the base metal plate to integrate the conductor lines so as to be linearly arranged, and in the two conductor lines, the arrangement on the side facing each other. An overlay dielectric provided so as to directly cover at least the entire line region along the direction, and an orthographic projection of the two line regions directly on the upper surface of the overlay dielectric, the overlay dielectric being provided directly on the overlay dielectric. A connecting strip for connecting the regions.

As described above, in the structure of the present invention, the distributed constant lines are coupled to each other by the structure in which the overlay dielectric and the coupling strip line are sequentially stacked instead of the conventional wire. Here, the line area is an area on the dielectric substrate on which the conductor line is provided, and the "line area on the side opposite to each other" includes an edge forming a gap between the chips provided opposite to each other. Side refers to a region on the upper surface of the dielectric substrate. The orthogonal projection region refers to a region on the upper surface of the overlay dielectric obtained by orthogonally projecting the line region provided with the overlay dielectric. In this way, by providing a coupling strip, which is a conductor, via an overlay dielectric, which is a dielectric, so as to overlap a part of each conductor line when viewed from above, distributed coupling between these conductor lines, that is, Electromagnetically coupled.
Therefore, the addition of inductance, which has been a problem in the prior art, is eliminated, and it is possible to connect the distributed constant lines at high frequencies in combination with the base metal plate that couples the ground conductors.

According to a preferred configuration example of the microwave circuit of the present invention, when the wavelength corresponding to the center frequency of the desired frequency band is λ, the length of the orthogonal projection region in the array direction is nλ. / 4 (however, n is an odd number).

As described above, when the length of the orthogonal projection region in the array direction is set to nλ / 4, when the frequency of the guided microwave signal is the frequency corresponding to the wavelength λ,
The conductor line and the coupling strip are short-circuited (Reference II; Fundamentals of microwave circuits and their applications, Figure 8. on page 303).
Published by General Electronic Publishing Company in 1990). Therefore, the conductor lines are short-circuited via the coupling strip, and the propagation characteristic of the microwave signal exhibits a band-pass type filter characteristic having this frequency as the center frequency. Therefore, since the inductance is not added and the characteristics of the microwave circuit are not deteriorated, it is possible to couple the distributed constant lines at high frequencies.

According to a preferred configuration example of the present invention,
The widths of the conductor line and the coupling strip and the thickness of the overlay dielectric included in the orthogonal projection region have a characteristic impedance Z0 of the conductor line, and an odd mode characteristic between the conductor line and the coupling strip. The impedance is Zodd, and the even mode characteristic impedance between the conductor line and the coupling strip is Zeve.
When n is set, Z0 = (Zeven-Zodd) / 2 is set.

As described above, by setting the sizes of the conductor line, the coupling strip, and the overlay dielectric included in the orthogonal projection region so that the above equation holds, the size between the coupling strip and each conductor line is set. Since the impedances are matched (Fig. 8.9, p.303 of document II), the voltage reflectance between the coupling strip and each conductor line can be made zero (p.9 of document II). Therefore, when the microwave signal is guided between the conductor lines through the coupling strip, there is no energy loss of the microwave signal. For the characteristic impedances of odd mode and even mode, see p.193 of Document II.

Further, according to a preferred configuration example of the microwave circuit of the present invention, the underlying metal plate included in the gap region between the orthogonal projection regions is in contact with the lower surface of the overlay dielectric. Characterize.

As described above, since the interval between the chips is uniquely determined by the shape of the underlying metal plate, the chips can be easily positioned on the underlying metal plate, and variations in this interval can be caused. It is possible to suppress the variation in the characteristics of the microwave circuit caused by it.

Further, according to a preferred configuration example of the microwave circuit of the present invention, when the wavelength corresponding to the center frequency of the desired frequency band is λ, the length of the orthogonal projection region in the arrangement direction is nλ. / 4 (where n is an odd number), and the length of the coupling strips included in the gap region in the arrangement direction is set to nλ / 2.

As described above, when the length of the orthogonal projection region in the arrangement direction is set to nλ / 4 and the length of the gap region in the arrangement direction is set to nλ / 2, it corresponds to the wavelength λ. At frequency, the conductor lines are short-circuited at high frequencies via the coupling strips. At this time, the propagation characteristic of the microwave signal guided becomes a band pass type filter characteristic having this frequency as the center frequency. Therefore, since the inductance is not added and the characteristics of the microwave circuit are not deteriorated, it is possible to couple the distributed constant lines at high frequencies.

According to a preferred embodiment of the present invention, the widths of the conductor lines and the coupling strips included in the orthogonal projection region and the thickness of the overlay dielectric, and the widths of the coupling strips included in the gap region and The thickness of the overlay dielectric defines the characteristic impedance of the conductor line as Z0, the odd-mode characteristic impedance between the conductor line and the coupling strip as Zodd,
When the even mode characteristic impedance between the conductor line and the coupling strip is set to Zeven, Z0 = (Zeven-Zodd) / 2 is set to be satisfied.

As described above, the sizes of the conductor lines, the coupling strips and the overlay dielectrics included in the orthogonal projection region and the sizes of the coupling strips and the overlay dielectrics included in the gap region are satisfied so that the above equation is satisfied. By setting and, the impedance between the coupling strip and each conductor line is matched (Reference II
(Fig. 8.9 on p. 303), the voltage reflectance between the coupling strip and each conductor line can be set to 0 (Ref. II, p.
9). Therefore, when the microwave signal is guided between the conductor lines through the coupling strip, there is no energy loss of the microwave signal.

According to a preferred configuration example of the microwave circuit of the present invention, the distributed constant line is a microstrip line.

The microstrip line is a signal transmission line in which a characteristic impedance formed by a dielectric (dielectric substrate) between a ground plane as a ground conductor and a wiring plane as a conductor line is controlled. The characteristic impedance can be changed by selecting the relative permittivity and thickness of the dielectric and the width and thickness of the wiring. In a high frequency circuit in the microwave band or higher, an arbitrary impedance can be realized by changing the length of the line, and thus it is often used in a distributed constant circuit such as an impedance matching circuit.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. It should be noted that the drawings are schematically shown to the extent that the configuration, size, and arrangement relationship of the present invention can be understood, and the numerical conditions and the like described below are merely examples. There is no limitation to the form.

[First Embodiment] FIG. 1 is a diagram showing the configuration of the first embodiment. 1B shows a perspective view, and FIG. 1A shows a cross-sectional view taken at a position of line aa in FIG. 1B. As shown in this figure, the first configuration example is a configuration including an overlay dielectric 22 and a coupling strip 24.

The configuration of this embodiment is such that the first chip 28
And the second chip 30 is provided on the base metal plate 10. The first chip 28 is formed by sequentially stacking the first ground conductor 12, the first dielectric substrate 14, and the first conductor line 36, and these form the first microstrip line 18 as a distributed constant line. are doing. The second chip 30 is composed of a second ground conductor 13, a second dielectric substrate 16, and a second conductor line 38, which are sequentially stacked, and these are the second microstrip line 20 as a distributed constant line. Are configured. The first and second conductor lines 36 and 38 have a quadrangular shape, and the chips 28 and 30 are positioned and provided on the base metal plate 10 so that they are linearly arranged.

The overlay dielectric 22 covers at least the entire line region of the two conductor lines 36 and 38 along the arrangement direction (direction indicated by arrow p in FIG. 1) on the side facing each other. In addition, the overlay dielectric 22 has a rectangular shape. The above-mentioned line region is a region on the upper surface of the first conductor line 36 in the range indicated by the arrow L ₁ in FIG.
Called 0. ) And a region on the upper surface of the second conductor line 38 in the range indicated by the arrow L ₂ (hereinafter referred to as the second line region 42). Thus, the overlay dielectric 22 bridges between the first and second conductor lines 36 and 38.

The coupling strip 24 is provided directly on the overlay dielectric 22 and has two line regions 40.
And 42 respectively to orthographically project regions 44 and 46 on the top surface of overlay dielectric 22. The first orthogonal projection region 44 connects the first line region 40 to the coupling strip 2
4 is an area obtained by orthographic projection on the upper surface of No. 4. Also, the second
The orthogonal projection area 46 is an area obtained by orthogonally projecting the second line area 42 on the upper surface of the coupling strip 24. As described above, the first configuration example includes the first and second orthogonal projection regions 44.
And 46 are linearly connected by a connecting strip 24.

The width W of the joining strip 24 of this configuration example
₂ is the width W _{1 of} the first and second conductor lines 36 and 38.
Is the same as In addition, the width W ₃ of the overlay dielectric 22 in this configuration example is about twice the width W ₂ of the coupling strip 24. And the thickness S of the overlay dielectric 22
Is the coupling strip 24 and the first and second conductor lines 3
It is made thinner than the thickness of the first and second dielectric substrates 14 and 16 for distributed coupling between 6 and 38.

In the first embodiment, Teflon is used as the overlay dielectric 22 and the coupling strip 24 is provided on the overlay dielectric 22. The longitudinal direction of the coupling strip 24 is set to the first and second conductors. Tracks 36 and 3
The overlay dielectric 22 is adhered to the conductor lines 36 and 38 with epoxy resin or the like so as to be aligned in the arrangement direction of 8.

As described above, in this first configuration example, the first conductor line 36 and the coupling strip 24 are distributed-coupled, and the second conductor line 38 and the coupling strip 24 are distributed.
And are distributed and coupled. Therefore, the first and second conductor lines 36 and 38 are distributedly coupled via the coupling strip 24. As described above, according to the first configuration example, the wire conventionally used for coupling is unnecessary. Therefore, when coupling the conductor lines, the inductance is not inserted in series with them. Therefore, the coupling strip 24 and the ground conductor 10
By the first and second microstrip lines 18
There is no deterioration of the guided microwave signal because of the high frequency coupling between 20 and 20.

[Second Embodiment] Next, the configuration of the second embodiment will be described with reference to FIG. This second
In the configuration of the embodiment, when the wavelength corresponding to the center frequency of the desired frequency band is λ, the lengths of the orthogonal projection regions 44 and 46 in the arrangement direction p are nλ / 4 (where n is an odd number).
The configuration is set to. Therefore, in the configuration of the first embodiment, the lengths L ₁ and L _{2 of} the first orthogonal projection region 44 and the second orthogonal projection region 46 in the arrangement direction p are nλ /
It has a configuration of four. As described in the first embodiment, the first conductor line 36 and the coupling strip 24 are distributed-coupled, and the second conductor line 38 and the coupling strip 24 are distributed-coupled. The first conductor line 36 and the second conductor line 38 are distributed-coupled. As described above, when the sizes of the orthogonal projection regions 44 and 46 are set, when the wavelength of the guided microwave signal is λ, the wavelength between the first conductor line 36 and the second conductor line 38 is λ. Are short-circuited at a frequency corresponding to (hereinafter, this frequency is represented by a center frequency f ₀ ) (reference II).

FIG. 2 is a graph schematically showing the signal propagation characteristic of the configuration of the second embodiment. The horizontal axis represents frequency and the vertical axis represents transmission coefficient S21 (S parameter) in dB. As shown in FIG. 2, the orthogonal projection region 44
When the sizes of 46 and 46 are set as above,
The frequency becomes ₀ dB at the frequency f ₀ , and therefore the loss becomes 0, and a pass band type filter characteristic having the frequency f ₀ as the center frequency is exhibited. Therefore, according to the second configuration example, since the inductance is not added as in the conventional case, the first and second microstrip lines can be coupled at a high frequency without deteriorating the propagation characteristics, which is desirable. Since it is possible to guide a microwave signal of a frequency between individual chips without loss, propagation characteristics in a high frequency band such as a millimeter wave band are improved.

It should be noted that the odd number n can be set to an appropriate odd number such as 1, 3 and 5, but it is optimal when the order is as low as possible, that is, when n = 1.

Also preferably, the orthogonal projection regions 44 and 4 are
The widths W ₁ and W _{2 of the} conductor lines 36 and 38 and the coupling strip 24 and the thickness S of the overlay dielectric 22 included in each of the six conductors 36 and 38 make the characteristic impedance of the conductor lines 36 and 38 Z0, and The odd mode characteristic impedance between the coupling strip 24 and the coupling strip 24 is Zodd, and the even mode characteristic impedance between the conductor lines 36 and 38 and the coupling strip 24 is Ze.
When it is set as ven, it is preferable that Z0 = (Zeven-Zodd) / 2 (1) is set. When the sizes of the first conductor line 36, the second conductor line 38, the coupling strip 24, and the overlay dielectric 22 are set so as to satisfy the expression (1), the coupling strip 24
Since the impedance between the coupling strip 24 and the first conductor line 36 is matched, and the impedance between the coupling strip 24 and the second conductor line 38 is matched, the coupling strip 24 and the first conductor line 36 are matched. The voltage reflectivity between them and the voltage reflectivity between the coupling strip 24 and the second conductor line 38 can be zero. Therefore, the first and second conductor lines 36 and 3 are connected via the coupling strip 24.
It is possible to reduce the energy loss of the microwave signal when the microwave signal is guided between 8 and therefore, it is expected to further improve the propagation characteristics.

[Third Embodiment] FIG. 3 is a diagram showing the configuration of the third embodiment. 3B shows a perspective view, and FIG. 3A shows a cross-sectional view taken along the line aa in FIG. 3B. As shown in this figure, the third configuration example includes the first and second orthogonal projection regions 4
The base metal plate 10 included in the gap region 48 between 4 and 46 is in contact with the lower surface of the overlay dielectric 22. The description of the same configuration as that of the first embodiment will not be repeated.

The structure of this embodiment is similar to that of the first embodiment in that the first chip 28 and the second chip 30 are provided on the base metal plate 10. The shapes are different. The base metal plate 10 has a convex portion 50, and the chips 28 and 30 are attached in such a manner that opposite side surfaces of the convex portion 50 are sandwiched from both sides. Therefore, when the base metal plate 10 is used, the distance between the first and second chips 28 and 30 becomes constant, and the chips can be easily positioned.

Further, the overlay dielectric 22 of this embodiment is provided so as to directly cover the entire first and second line regions 42 and 44 of the two conductor lines 36 and 38, and in addition, The lower surface of the overlay dielectric 22 included in the gap region 48 (the region within the range indicated by the arrow L ₃ in FIG. 3) that is the region between the first and second line regions 42 and 44 is provided with the convex portion 50 of the underlying metal plate 10. Is in contact with the upper surface of the. Thus, the overlay dielectric 22 bridges between the first and second conductor lines 36 and 38.

The connecting strip 24 of this structural example is
Width W in the first and second orthographic projection regions 44 and 46_Two 
And the coupling strip 24 included in the gap region 48
Width W_Four Is different from. This width W_Four And over
-Thickness S of Ray Dielectric 22_Two(Included in the gap region 48
The thickness of the part to be connected) is set according to
Characteristic impedance of each conductor line 36 and 38
Can be matched to the sex impedance. This practice
In the form of, the width W of the coupling strip is_Two Is the first and
Width W of the second conductor lines 36 and 38₁ Set the same width as
ing. In addition, the overlay dielectric 22 of this configuration example
Width W_Three Is the width W of the connecting strip 24 _Two About twice
is there. Then, the line region 40 of the overlay dielectric 22
And the thickness S on 42₁ Is the connecting strip 24 and the
Distributed coupling between the first and second conductor lines 36 and 38
Of the first and second dielectric substrates 14 and 16
It is thinner than the thickness.

As described above, in this third configuration example, the first conductor line 36 and the coupling strip 24 are distributed-coupled, and the second conductor line 38 and the coupling strip 24 are distributed.
And are distributed and coupled. Therefore, since the first and second conductor lines 36 and 38 are distributed and coupled via the coupling strip 24, the wire conventionally used for coupling is unnecessary, and when the conductor lines are coupled, these wires are not necessary. Inductance is not inserted in series. Therefore, since the coupling strip 24 and the ground conductor 10 couple the first and second microstrip lines 18 and 20 at high frequencies, there is no deterioration of the guided microwave signal. Further, since the interval between the chips is uniquely determined by the shape of the underlying metal plate, it is possible to easily position the chip on the underlying metal plate, and the microwave circuit caused by the variation in the interval can be used. It is possible to suppress variations in characteristics.

[Fourth Embodiment] Next, the configuration of the fourth embodiment will be described with reference to FIG. This fourth
In the configuration of the embodiment, when the wavelength corresponding to the center frequency of the desired frequency band is λ, the lengths of the orthogonal projection regions 44 and 46 in the arrangement direction p are nλ / 4 (where n is an odd number).
And the length of the coupling strip 24 included in the gap region 48 in the arrangement direction p is set to nλ / 2.

As described in the first and third embodiments, the first conductor line 36 and the coupling strip 24 are distributed-coupled, and the second conductor line 38 and the coupling strip 24 are distributed.
Is distributedly coupled to the first conductor line 36.
And the second conductor line 38 are distributedly coupled. As described above, when the sizes of the orthogonal projection regions 44 and 46 and the size of the coupling strip 24 included in the gap region 48 are set, when the wavelength of the guided microwave signal is λ, the first conductor line is formed. Between 36 and the second conductor line 38,
It is short-circuited at the frequency f ₀ corresponding to the wavelength λ (reference II).

This means that, as shown in FIG. 2, the propagation characteristic of the microwave signal becomes ₀ dB at the frequency f ₀ , and therefore the loss becomes 0, which indicates the pass band type filter characteristic having the frequency f ₀ as the center frequency. become. Therefore, according to the fourth configuration example, since the inductance is not added unlike the conventional case, the propagation characteristic is not deteriorated and the first characteristic is applied in high frequency.
Since it is possible to couple between the second microstrip line and the microwave signal of a desired frequency can be guided between the individual chips without loss, a high frequency such as a millimeter wave band can be obtained. The propagation characteristic in the band is improved.

It should be noted that the odd number n can be set to an appropriate odd number such as 1, 3, and 5, but it is optimal when the order is as low as possible, that is, when n = 1.

Also, preferably, the orthogonal projection regions 44 and 4 are
6, the conductor lines 36 and 38, the widths W ₁ and W _{2 of the} coupling strip 24, and the overlay dielectric 22, respectively.
Thickness S ₁ , the width W ₄ of the coupling strip contained in the gap region 48, and the thickness S ₂ of the overlay dielectric 22 make the characteristic impedance of the conductor lines 36 and 38 Z.
0, Zodd is the odd-mode characteristic impedance between the conductor lines 36 and 38 and the coupling strip 24, and Zeven is the even-mode characteristic impedance between the conductor lines 36 and 38 and the coupling strip 24.
It is preferable that the above-mentioned (1) is set. The sizes of the first conductor line 36, the second conductor line 38, the coupling strip 24, and the overlay dielectric 22 (and the size of the convex portion 50 of the base metal plate 10) are (1).
When set to satisfy the equation, the impedance between the coupling strip 24 and the first conductor line 36 is matched, and the impedance between the coupling strip 24 and the second conductor line 38 is matched. Therefore, the voltage reflectance between the coupling strip 24 and the first conductor line 36 and the voltage reflectance between the coupling strip 24 and the second conductor line 38 can be made zero. Therefore, when the microwave signal is guided between the first and second conductor lines 36 and 38 through the coupling strip 24, it is possible to reduce the energy loss of the microwave signal. It can be expected to further improve the propagation characteristics.

[0043]

According to the microwave circuit of the present invention, it is possible to provide a distributed coupling between conductor lines by providing an overlay dielectric and a coupling strip instead of conventional wires. The addition of inductance, which has been a problem in the past, is eliminated, and it becomes possible to connect the distributed constant lines at high frequencies in combination with the underlying metal plate that couples the ground conductors.

Further, according to the microwave circuit of the present invention, the wavelength corresponding to the center frequency of the desired frequency band is set to λ.
, The length of the orthogonal projection region in the array direction is nλ / 4
By setting (where n is an odd number), the conductor lines are short-circuited via the coupling strip, and the propagation characteristics of the microwave signal show a band-pass type filter characteristic with this frequency as the center frequency. become. Therefore, since the inductance is not added and the characteristics of the microwave circuit are not deteriorated, it is possible to couple the distributed constant lines at high frequencies.

Further, according to the microwave circuit of the present invention, the conductor lines, the coupling strips and the overlay dielectrics included in the orthogonal projection region have respective sizes such that the characteristic impedance of the conductor lines is Z0, the conductor lines and the coupling strips. Let Zodd be the odd-mode characteristic impedance between and, and Zeven be the even-mode characteristic impedance between the conductor line and the coupling strip. By setting Z0 = (Zeven-Zodd) / 2, Since the impedance between the coupling strip and each conductor line is matched, the voltage reflectance between the coupling strip and each conductor line can be set to zero. Therefore, when the microwave signal is guided between the conductor lines through the coupling strip, there is no energy loss of the microwave signal.

Further, according to the microwave circuit of the present invention, since the underlying metal plate included in the gap region between the orthogonal projection regions is in contact with the lower surface of the overlay dielectric, the distance between the chips is reduced. Since it is uniquely determined by the shape of the base metal plate, it is possible to easily position the chip on the base metal plate, and it is possible to suppress variations in the characteristics of the microwave circuit due to variations in this interval. it can.

According to the microwave circuit of the present invention, the wavelength corresponding to the center frequency of the desired frequency band is set to λ.
, The length of the orthogonal projection region in the array direction is nλ / 4.
(Where n is an odd number), and the length of the coupling strips included in the gap region in the arrangement direction is nλ / 2.
Therefore, the conductor lines are short-circuited at a high frequency through the coupling strip at the frequency corresponding to the wavelength λ, and the propagation characteristics of the microwave signal guided at this time are centered at this frequency. The band-pass filter characteristic is exhibited. Therefore, since the inductance is not added and the characteristics of the microwave circuit are not deteriorated, it is possible to couple the distributed constant lines at high frequencies.

According to the microwave circuit of the present invention, the conductor line, the coupling strip, and the overlay dielectric included in the orthogonal projection region and the gap region have the characteristic impedance Z0 and the conductor line, respectively. When the odd mode characteristic impedance between the coupling strip and the even mode characteristic impedance between the conductor line and the coupling strip is Zodd, Z0 = (Zeven-Zodd) / 2 is set to hold. By doing so, the impedance between the coupling strip and each conductor line is matched, so that the voltage reflectance between the coupling strip and each conductor line can be set to zero. Therefore, when the microwave signal is guided between the conductor lines through the coupling strip, there is no energy loss of the microwave signal.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a configuration of a first embodiment.

FIG. 2 is a diagram showing a signal propagation characteristic of the embodiment.

FIG. 3 is a diagram illustrating a configuration of a third embodiment.

FIG. 4 is a diagram showing a conventional configuration.

[Explanation of symbols]

 10: Base Metal Plate 12: First Grounding Conductor 13: Second Grounding Conductor 14: First Dielectric Substrate 16: Second Dielectric Substrate 18: First Microstrip Line 20: Second Microstripline 22: Overlay Dielectric 24: Coupling strip 26: Wire 28: First chip 30: Second chip 32: First distributed constant line 34: Second distributed constant line 36: First conductor line 38: Second conductor line 40: First line region 42: 2nd track | line area 44: 1st orthogonal projection area 46: 2nd orthogonal projection area 48: Gap area 50: Convex part

Claims (7)

[Claims] 1. A ground metal plate is provided with two chips each having a distributed constant line composed of a conductor line, a dielectric substrate and a ground conductor, whereby the ground conductor is coupled with the ground metal plate. In a microwave circuit integrated so that the conductor lines are linearly arranged, at least directly covering at least the entire line regions along the arrangement direction on the opposite sides of the two conductor lines. An overlay dielectric provided, and a coupling strip directly on the overlay dielectric that couples each of the two line regions to an orthographic region of the top surface of the overlay dielectric. And microwave circuit. 2. The microwave circuit according to claim 1, wherein when the wavelength corresponding to the center frequency of the desired frequency band is λ, the length of the orthogonal projection region in the array direction is nλ /
A microwave circuit, wherein the microwave circuit is set to 4 (where n is an odd number). 3. The microwave circuit according to claim 1, wherein the width of the conductor line and the coupling strip included in the orthogonal projection region and the thickness of the overlay dielectric make the characteristic impedance of the conductor line Z0, The odd mode characteristic impedance between the conductor line and the coupling strip is Zodd, and the even mode characteristic impedance between the conductor line and the coupling strip is Zeve.
A microwave circuit, wherein Z0 = (Zeven-Zodd) / 2 when n is set. 4. The microwave circuit according to claim 1, wherein the underlying metal plate included in the gap region between the orthogonal projection regions is in contact with a lower surface of the overlay dielectric. Wave circuit. 5. The microwave circuit according to claim 4, wherein when the wavelength corresponding to the center frequency of the desired frequency band is λ, the length of the orthogonal projection region in the array direction is nλ /
4 (where n is an odd number) and the length of the coupling strips included in the gap region in the arrangement direction is set to nλ / 2. 6. The microwave circuit according to claim 5, wherein the width of the conductor line and the coupling strip included in the orthogonal projection region, the thickness of the overlay dielectric, and the coupling strip included in the gap region. The width and the thickness of the overlay dielectric make the characteristic impedance of the conductor line Z0 and the odd mode characteristic impedance between the conductor line and the coupling strip Zo.
dd, when the even mode characteristic impedance between the conductor line and the coupling strip is Zeven, it is set such that Z0 = (Zeven-Zodd) / 2. . 7. The microwave circuit according to any one of claims 1 to 6, wherein the distributed constant line is a microstrip line.