CN104868214B - Balanced type transition circuit based on the micro-strip of probe feed to substrate integration wave-guide - Google Patents

Abstract

The invention discloses a balanced transition circuit based on a microstrip substrate integrated waveguide fed by a probe, including first to third dielectric substrates, first and second metal patches, four input and output transmission lines and four A resonator; the second and third dielectric substrates are provided with first metallized through holes to form a substrate integrated waveguide, and the first metal patch constitutes the ground of the input and output transmission lines; the resonator is arranged on the upper surface of the third dielectric substrate; The second metal patch constitutes the ground of the substrate integrated waveguide; four second metallized through holes penetrate the first dielectric substrate, the first metal patch and the second dielectric substrate. The input/output transmission line is fed into the substrate integrated waveguide through the second metallized via hole and the resonator separated by half wavelength, so that the differential signal passes through, the common mode signal is suppressed, and the resonator is equivalent to the bottom surface of the underlying substrate integrated waveguide Capacitance reduces the requirement on the length of the probe, thereby reducing the requirement on the thickness of the integrated waveguide on the substrate and reducing the thickness of the circuit.

Description

Balanced Transition Circuit Based on Probe-fed Microstrip-Substrate Integrated Waveguide

technical field

The invention relates to the communication field, more specifically, to a balanced transition circuit based on a microstrip substrate integrated waveguide fed by a probe.

Background technique

In microwave and millimeter wave commercial and military communication systems, microstrip and substrate-integrated waveguides are two commonly used transmission lines that can efficiently transmit high-frequency signals between various modules. Microstrip transmission lines are commonly used to connect multiple active circuit modules including transistors, monolithic microwave integrated circuits (MMICs), and various surface-mounted components. Since the substrate-integrated waveguide has the characteristics of high Q value, low loss and large power capacity of the metal waveguide, and is easy to process and planarly integrated, it has become the first choice for low-loss transmission lines such as antenna feed networks and high-quality factor filters.

In a system architecture design, it is advantageous to use different types of transmission lines, such as microstrip lines and substrate-integrated waveguides coexisting in modules. In this regard, a transition device from microstrip to SIWG is required when the SIWG module is connected to the microstrip module. In many applications, these transition devices are mounted on the surface of multi-layer panels. The design of broadband microstrip-substrate integrated waveguide transition based on planar substrate, easy to manufacture and compact size is very important.

Due to the symmetry of the circuit form and the anti-phase characteristics of the signal, the balanced circuit has received more and more research and attention. Compared with traditional single-ended microwave circuits, the advantages of balanced circuits include: harmonic suppression, high linearity, strong anti-interference ability (usually external noise is a common-mode signal), high reliability and high output power (two Differential circuit power combination), etc. Therefore, in current microwave monolithic integrated circuits (MMICs) and radio frequency integrated circuits (RFICs), balanced/differential modes are widely used. Therefore, it is very necessary to develop a balanced transition design of microstrip-substrate integrated waveguide for use in balanced circuits.

Most of the traditional balanced transition designs from the microstrip to the substrate integrated waveguide are composed of different forms of probe feeding. Among them, the better design is to extend the probe into the substrate integrated waveguide and couple with the substrate integrated waveguide. , but because the probe feed needs a certain length, which makes the thickness of the substrate relatively thick, and the selection of the substrate is difficult. For the operating bandwidth, this type of design is 17%, and the performance of this type of design is not evaluated in terms of common mode rejection.

Contents of the invention

The present invention aims at the traditional probe feeding to realize the transition from the microstrip to the integrated waveguide of the substrate, resulting in a large thickness of the substrate and the inconvenient selection of the substrate caused by strict requirements on the thickness of the substrate. The balanced transition circuit of the electric microstrip to the substrate integrated waveguide realizes the multi-layer heteroplane transition of the differential signal from the microstrip transmission line to the substrate integrated waveguide transmission, simplifies the circuit structure, reduces the thickness, and is easy to manufacture, increasing the Differential mode bandwidth, good common mode suppression effect, strong anti-interference ability and high reliability.

The technical solution adopted by the present invention to solve the technical problem is to provide a balanced transition circuit based on the microstrip substrate integrated waveguide fed by probes, including a first dielectric substrate, a second dielectric substrate, a third dielectric substrate, The first metal patch, the second metal patch, two input and output transmission line groups, and four resonators; the two input and output transmission line groups are symmetrically arranged at both ends of the upper surface of the first dielectric substrate, and each of the The input/output transmission line set includes two input/output transmission lines mirrored; the lower surface of the first dielectric substrate is connected to the upper surface of the second dielectric substrate; the second dielectric substrate and the third dielectric substrate A plurality of first metallized through-holes are respectively provided to form a substrate integrated waveguide, and the first metal patch is provided on the upper surface of the second dielectric substrate to form the ground of the input-output transmission line group; The lower surface of the second dielectric substrate is connected to the upper surface of the third dielectric substrate; the four resonators are symmetrically arranged in groups of two at both ends of the upper surface of the third dielectric substrate; the second metal sticker The chip is arranged on the lower surface of the third dielectric substrate to form the ground of the integrated waveguide of the substrate; four second metallized through holes are arranged symmetrically in groups of two at both ends of the first dielectric substrate and pass through the first The dielectric substrate, the first metal patch and the second dielectric substrate; the two second metallized through holes in one group are respectively connected to the positions of the input/output ends of the two input/output transmission lines on the same side and The central positions of the two resonators on the same side are corresponding; the distance between the two second metallized through holes in one group is half a wavelength.

Preferably, the plurality of first metallized vias form a rectangle.

Preferably, the second dielectric substrate and the third dielectric substrate further include a sensing window composed of a plurality of third metallized through holes.

Preferably, the inductive window is located at the center of the rectangle surrounded by the plurality of first metallized through holes.

Preferably, the inductive window is rectangular and consists of four groups of third metallized through holes respectively located at four vertices of the rectangle, and each group includes two third metallized through holes.

Preferably, the resonator is a rectangular metal patch.

The balanced transition circuit based on the probe-fed microstrip to the substrate integrated waveguide of the present invention has the following beneficial effects: the input/output transmission line of the balanced transition passes through the probes formed by the second metallized through holes separated by a half-wavelength. The resonator is fed into the substrate-integrated waveguide, so that the differential signal passes through and the common-mode signal is suppressed. The chip resonator and the bottom surface of the underlying substrate-integrated waveguide (consisting of the third dielectric substrate and the first metallized through hole) are formed The equivalent capacitance can reduce the requirement on the length of the probe, thereby reducing the requirement on the thickness of the integrated waveguide on the substrate and reducing the thickness of the circuit.

In addition, the bandwidth of the differential mode response is increased by adding an inductive window formed by a metallized through hole in the substrate integrated waveguide. At the same time, the suppression ability of the common mode signal is evaluated, and it has a good common mode suppression effect.

Description of drawings

Fig. 1 is the three-dimensional structure schematic diagram of the first embodiment of the balanced transition circuit based on the probe-fed microstrip substrate integrated waveguide of the present invention;

Fig. 2 is the side view of the first embodiment of the balanced transition circuit based on probe-fed microstrip substrate integrated waveguide of the present invention;

3 is a topological structure diagram of the circuit on the upper surface of the first dielectric substrate in the first embodiment of the balanced transition circuit based on the probe-fed microstrip substrate integrated waveguide of the present invention;

Fig. 4 is a topological structure diagram of the first metal patch in the first embodiment of the balanced transition circuit based on the probe-fed microstrip substrate integrated waveguide of the present invention;

5 is a topological structure diagram of the second dielectric substrate in the first embodiment of the balanced transition circuit based on the probe-fed microstrip substrate integrated waveguide of the present invention;

6 is a topological structure diagram of the upper surface of the third dielectric substrate in the first embodiment of the balanced transition circuit based on the probe-fed microstrip substrate integrated waveguide of the present invention;

FIG. 7 is a simulation result diagram of a first example of a balanced transition circuit based on a probe-fed microstrip to a substrate-integrated waveguide of the present invention.

Detailed ways

The present invention will be further explained below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is a three-dimensional structural schematic diagram of a first embodiment of a balanced transition circuit 100 based on a probe-fed microstrip substrate integrated waveguide of the present invention, as shown in Fig. 1 , in this embodiment, based on a probe-fed The balanced transition circuit 100 of electric microstrip substrate integrated waveguide includes a first dielectric substrate 1, a second dielectric substrate 2, a third dielectric substrate 3, a first metal patch 4, a second metal patch 5, two Input and output transmission line group 6 and four resonators 7 .

Wherein, two input/output transmission line groups 6 are arranged symmetrically at both ends of the upper surface of the first dielectric substrate 1, and each input/output transmission line group 6 includes two input/output transmission lines arranged in mirror images, for example, at the left end of the first dielectric substrate 1 Two input transfer lines set for mirroring, and two output transfer lines for mirroring on the right. If the left end of the first dielectric substrate 1 is two output transmission lines, the right end is two input transmission lines. The lower surface of the first dielectric substrate 1 is connected to the upper surface of the second dielectric substrate 2 .

The second dielectric substrate 2 and the third dielectric substrate 3 are respectively provided with a plurality of first metallized through holes 8 , and the plurality of first metallized through holes 8 are evenly distributed to form a rectangle to form a substrate integrated waveguide. The first metal patch 4 is disposed on the upper surface of the second dielectric substrate 2 to form the ground of the input and output transmission line group 6 . The lower surface of the second dielectric substrate 2 is connected to the upper surface of the third dielectric substrate 3 . The four resonators 7 are symmetrically arranged in groups of two by two at both ends of the upper surface of the third dielectric substrate 3 . In this embodiment, the resonators 7 are rectangular metal patches. The second metal patch 5 is disposed on the lower surface of the third dielectric substrate 3 to form the ground of the substrate integrated waveguide.

The four second metallized through holes 9 are symmetrically arranged in two groups at both ends of the first dielectric substrate 1, and the four second metallized through holes 9 all pass through the first dielectric substrate 1, the first metal patch 4 and the second dielectric substrate 1. Two dielectric substrates 2 . The second metallized through hole 9 is the probe. The two second metallized through holes 9 in each group are half a wavelength apart, and correspond to the positions of the input/output ends of the two input/output transmission lines on the same side and the center positions of the two resonators 7 on the same side respectively . For example, if there are two input transmission lines on the left side of the first dielectric substrate 1, the positions of the two second metallized through holes 9 on the left side correspond to the positions of the input ends of these two input transmission lines, and also correspond to the positions of the two input terminals on the same side. There is a one-to-one correspondence between the center positions of each resonator 7 . That is to say, the input/output ends of the two input/output transmission lines on the same side are half a wavelength apart, and the centers of the two resonators 7 on the same side are half a wavelength apart.

In addition, in the center of the rectangle surrounded by the plurality of first metallized through holes 8 on the second dielectric substrate 2 and the third dielectric substrate 3, a sensitive window composed of a plurality of third metallized through holes 10 is respectively provided, Preferably, the inductive window is rectangular and consists of four groups of third metallized through holes 10 arranged at its four vertices, and each group includes two third metallized through holes 10 .

In this embodiment, the dielectric constants of the first dielectric substrate 1 , the second dielectric substrate 2 and the third dielectric substrate 3 are the same, which can be realized by, for example, a Ro4003C high-frequency PCB board. In other embodiments, the dielectric constants of the first dielectric substrate 1 , the second dielectric substrate 2 and the third dielectric substrate 3 may also be different.

2 to 6 (for example and experimental measurement only, not for limiting the present invention), in one example, the thickness h1 of the first dielectric substrate 1=0.913mm, the thickness h2=0.913mm of the second dielectric substrate 2, The third dielectric substrate 3 thickness h3=0.254mm, the dielectric constant εr=3.38 of the first dielectric substrate 1, the second dielectric substrate 2 and the second dielectric substrate 3, long L1=77mm, wide L2=30mm (the first in the example to the same length and width as the third dielectric substrate). The input/output transmission line is divided into four sections, the first section is perpendicular to the long side of the first dielectric substrate 1, its length l1=6.9mm, its width W1=2.1mm, and its distance l4= from the short side of the first dielectric substrate 1 8.4mm; the second section is perpendicular to the first section, its length l2 = 6.6mm; the third section is perpendicular to the second section, its length l3 = 5mm, between the third section of the two input/output transmission lines mirrored Distance g=0.5mm; one end of the fourth section is connected to the third section, the other end is the input/output end and the distance ld=10.5mm, the length of the fourth section l5=8.65mm, the width of the fourth section W3=1mm, the fourth section The ends of the four sections are connected with a semicircle with a diameter d1=1.2mm. The length and width of the first metal patch 4 are the same as that of the dielectric substrate, the outer ring diameter D=2mm and the inner ring diameter d2=1mm of the second metallized through hole 9 passing through the first metallized patch 4, the first metallized patch 4 The distance fv1=12.7mm between the short side of the sheet 4 and the nearest second metallization through hole 9, the distance between two second metallization through holes 9 in one group is fv2=10.5mm, the second metallization The shortest distance fv3=7mm between the through hole 9 and the long side of the first metallization patch 4 .

On the second dielectric substrate 2 and the third dielectric substrate 3, the two shorter parallel sides of the rectangle surrounded by the first metallized through hole 8 and the two shorter parallel sides of the second dielectric substrate 2 and the third dielectric substrate 3 The distances are equal, the distance V1 = 7.9 mm. The distance between the two longer parallel sides of the rectangle surrounded by the first metallized through hole 8 and the two longer parallel sides of the second dielectric substrate 2 and the third dielectric substrate 3 can be equal or different, as shown in FIG. 5 . equal, one of the longer parallel sides of the rectangle surrounded by the first metallized through hole 8 is very close to the longer parallel sides of the second dielectric substrate 2 and the third dielectric substrate 3, and the other longer parallel side is closer to the second The distance V2 between the sides parallel to the dielectric substrate 2 and the third dielectric substrate 3 = 14.4 mm. As shown in Figures 5 and 6, the rectangular sensing window is located at the center of the rectangle surrounded by the first metallized through hole 8, and the distances from the rectangular sensing window to the two vertical sides of the rectangle surrounded by the first metallized through hole 8 are respectively are lg=1.5mm and lv1=23.75mm, and the distances from the rectangle surrounded by the first metallized through hole 8 are respectively lg=1.5mm, and the length of parallel sides is lv2=12.5mm. The diameter Vd of the first metallized via hole 8 , the second metallized via hole 9 and the third metallized via hole 10 is Vd=0.5 mm. The shortest distance lt1=5.05mm between the second metallized through hole 9 penetrating through the second dielectric substrate 2 and the short side of the rectangle surrounded by the first metallized through hole 8 is 5.05 mm, and the distance from the rectangle surrounded by the first metallized through hole 8 is The distance lt2 of the long sides is 6.3 mm, and the distance ltd of the two second metallized through holes 9 in one group is 10.5 mm.

The resonator 7 arranged on the upper surface of the third dielectric substrate 3 has a length lp1=10mm, a width lp2=7.5mm, and the shortest distance v1=1.55mm between the resonator 7 and the short side of the rectangle surrounded by the first metallized through hole 8 , the shortest distance v2=1.55mm between the resonator 7 and the long side of the rectangle surrounded by the first metallized through hole 8 . The distance between two adjacent sides of two resonators 7 in one group is gp=3mm.

The result of simulating the transition circuit 100 with the above parameters by the simulation software CST (Computer Simulation Technology) is shown in Fig. 7. It can be seen from Fig. 7 that the frequency range of the transition satisfying the return loss of less than 15dB is 8.52-11.26 GHz, That is, the relative bandwidth is 27.4%, and the common-mode signal suppression in the passband is above 19dB.

In the first embodiment of the balanced transition circuit 100 based on the probe-fed microstrip to the substrate integrated waveguide of the present invention, the input/output transmission line 6 passes through the probe composed of the second metallized through-hole 9 separated by a half-wavelength The resonator 7 formed with the rectangular metal patch is fed into the substrate integrated waveguide, so that the differential signal passes through, and the common mode signal is suppressed. The rectangular metal patch and the substrate integrated waveguide below (by the third dielectric substrate 3 and the first The equivalent capacitance formed on the bottom surface of the metallized through hole 8) can reduce the requirement on the length of the probe, thereby reducing the requirement on the thickness of the integrated waveguide on the substrate and reducing the thickness of the circuit. At the same time, the bandwidth is increased by adding the perceptual window.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of the claims of the present invention.

Claims (4)

1. a kind of balanced type transition circuit based on the micro-strip of probe feed to substrate integration wave-guide, it is characterised in that including One medium substrate (1), second medium substrate (2), the 3rd medium substrate (3), the first metal patch (4), the second metal patch (5), two input and output transmission line groups (6) and four resonators (7), the resonator (7) are the metal patch of rectangle；Two A input and output transmission line group (6) is symmetrically disposed on first medium substrate (1) the upper surface both ends, each input Output transmission line group (6) includes two input/output transmission lines that mirror image is set；The lower surface of the first medium substrate (1) It is connected with the upper surface of the second medium substrate (2)；On the second medium substrate (2) and the 3rd medium substrate (3) Multiple first plated-through holes (8) are respectively arranged with to form substrate integration wave-guide, multiple first plated-through holes (8) are uniformly divided Cloth and rectangle is surrounded, the upper surface that first metal patch (4) is arranged at the second medium substrate (2) is described defeated to form Enter the ground of output transmission line group (6)；The lower surface of the second medium substrate (2) and the upper table of the 3rd medium substrate (3) Face connects；Four resonators (7) are symmetrically disposed on the both ends of the 3rd medium substrate (3) upper surface in pairs；Institute State the second metal patch (5) and be arranged at the lower surface of the 3rd medium substrate (3) to form the ground of substrate integration wave-guide；Four Second plated-through hole (9) is symmetrically disposed on first medium substrate (1) both ends and runs through the first medium in pairs Substrate (1), first metal patch (4) and the second medium substrate (2)；Two second metallization in one group Through hole (9) is humorous with two of the position of the input/output terminal of two input/output transmission lines of the same side and the same side respectively Shake device (7) center it is corresponding；Two second plated-through holes (9) in one group are at a distance of half wavelength.

2. the balanced type transition circuit according to claim 1 based on the micro-strip of probe feed to substrate integration wave-guide, its It is characterized in that, is further included on the second medium substrate (2) and the 3rd medium substrate (3) logical by multiple three metallization The perceptual window that hole (10) is formed.

3. the balanced type transition circuit according to claim 2 based on the micro-strip of probe feed to substrate integration wave-guide, its It is characterized in that, the perception window is located at the center that multiple first plated-through holes (8) surround rectangle.

4. the balanced type transition circuit according to claim 3 based on the micro-strip of probe feed to substrate integration wave-guide, its It is characterized in that, the perception window is rectangle, is made of four group of the 3rd plated-through hole (10) for being located at four vertex of rectangle respectively, Every group includes two the 3rd plated-through holes (10).