CN105322259B

CN105322259B - Differential Bandpass Filter Based on Half-Mode Substrate Integrated Waveguide Structure

Info

Publication number: CN105322259B
Application number: CN201410341381.XA
Authority: CN
Inventors: 康炜; 沈义进; 周恺; 吴文
Original assignee: Nanjing University of Science and Technology
Current assignee: Nanjing University of Science and Technology
Priority date: 2014-07-17
Filing date: 2014-07-17
Publication date: 2019-05-07
Anticipated expiration: 2034-07-17
Also published as: CN105322259A

Abstract

The invention provides a differential bandpass filter based on a half-mode substrate integrated waveguide structure, comprising a dielectric substrate, a metal layer on the upper surface and a metal layer on the lower surface. The metallized through hole array, the upper surface metal layer and the lower surface metal layer enclose two half-mode resonant cavities. Compared with the realization of the traditional substrate-integrated waveguide filter, the size is reduced by half while maintaining the original performance, and the two transmission zeros can be changed by changing the position of the perturbation slot line. The invention effectively reduces the size of the filter, the size is half of that of the substrate integrated waveguide structure, and at the same time has a higher common mode suppression level, which is convenient for system integration.

Description

Differential bandpass filter based on half module substrate integrated wave guide structure

Technical field

The present invention relates to difference filter fields, in particular to a kind of difference based on half module substrate integrated wave guide structure Divide bandpass filter.

Background technique

Filter is important one of the basic element circuit of circuit system, is widely used in microwave communication, radar navigation, electricity It is indispensable important in microwave and millimeter-wave systems in the systems such as sub- confrontation, satellite communication, trajectory guidance, test instrumentation Device.The superiority and inferiority of its performance often directly affects the performance indicator of entire communication system.In practical engineering applications, from filtering Device technical indicator give processing finished product required time will be shorter and shorter, fast and accurately design high performance microwave Filter by be engineering design and market competition inexorable trend, design performance is high, small in size, at low cost and shorten filter and grind Period processed is the inevitable requirement of market competition.

Differential bandpass filter obtains special attention because of the signal-to-noise ratio having had, wherein differential signal selective filter It is most important index with common-mode signal inhibition.

Substrate integration wave-guide (SIW) is a kind of new microstrip line transmission form, real on dieelctric sheet using plated through-hole The field communication mode of existing waveguide.One critical nature of such waveguide be have with propagation characteristic similar in traditional rectangular waveguide, Such as quality factor are high, easily designed while more compact compared with conventional waveguide, have it is small in size, light-weight, be easily worked sum aggregate At the advantages that.And half module substrate integrated wave guide (HMSIW) technology based on substrate integration wave-guide further reduces filter The filter volume of size, half module substrate integrated wave guide is smaller, maintain high-performance, high q-factor, low-loss, low cost, easily In integrated advantage.

Therefore, how substrate integrated waveguide technology to be introduced into the design of differential bandpass filter, is difference bandpass filtering Urgent problem in device design.

Summary of the invention

It is an object of that present invention to provide a kind of differential bandpass filters based on half module substrate integrated wave guide structure, have more Good common mode inhibition level and two transmission zeros improves the selectivity of bandpass filter.

Above-mentioned purpose of the invention realizes that dependent claims are to select else or have by the technical characteristic of independent claims The mode of benefit develops the technical characteristic of independent claims.

To reach above-mentioned purpose, the technical solution adopted in the present invention is as follows:

A kind of differential bandpass filter based on half module substrate integrated wave guide structure comprising medium substrate, and setting In the upper surface metal layer and lower surface metal layer of medium substrate surface, medium substrate has a horizontal axis and vertical axis, Vertical axis is identical as the transmission direction of signal, in which:

Multiple perforative plated-through holes are formed in the medium substrate, upper surface metal layer and lower surface metal layer, Plated-through hole is in upper surface metal layer and lower surface metal layer surface composition through-hole array, the through-hole array, upper surface gold Belong to layer and lower surface metal layer and surrounds two and half mode resonant cavities, respectively the first half mode resonant cavities and the second half mode resonant cavities, the Half mode resonant cavity and the second half mode resonant cavities are symmetrical about horizontal axis, and the first half mode resonant cavities and the second half mode resonant cavities Adjoining position is formed with the first coupling window and the second coupling window；

Level on the edge of the upper surface metal layer about the first coupling window or the second coupling window is right Position is claimed to be formed with the first disturbance line of rabbet joint and the second disturbance line of rabbet joint；

Four feeder lines are arranged in the first half mode resonant cavity and the aperture position of the second half mode resonant cavity two sides, and respectively the One feeder line, the second feeder line, third feeder line and the 4th feeder line are transmitted for signal.

A kind of above-mentioned difference band logical based on half module substrate integrated wave guide structure is also proposed according to another aspect of the present invention The implementation method of filter, manufacturing process the following steps are included:

Install surface metal-layer and lower surface metal layer, aforementioned medium base respectively on two surfaces of a medium substrate The vertical axis of plate and the transmission direction of signal are identical；

It is logical that multiple perforative metallization are formed in the medium substrate, upper surface metal layer and lower surface metal layer surface Hole passes through the through-hole battle array by plated-through hole in upper surface metal layer and lower surface metal layer surface composition through-hole array Column, upper surface metal layer and lower surface metal layer enclose packet two and half mode resonant cavities of formation, respectively the first half mode resonant cavities and the 2 half mode resonant cavities, wherein the first half mode resonant cavities and the second half mode resonant cavities are configured to symmetrical about horizontal axis, and The first half mode resonant cavities are formed with first with the second half mode resonant cavity adjoining positions and couple window and the second coupling window；

Level on the edge of the upper surface metal layer about the first coupling window or the second coupling window Symmetric position forms the first disturbance line of rabbet joint and the second disturbance line of rabbet joint；

Four feeder lines are arranged in aperture position in the first half mode resonant cavity and the second half mode resonant cavity two sides, respectively First feeder line, the second feeder line, third feeder line and the 4th feeder line are transmitted for signal.

Detailed description of the invention

Fig. 1 is that the structure of differential bandpass filter of an embodiment of the present invention based on half module substrate integrated wave guide structure is shown It is intended to.

Fig. 2 is the side view of the differential bandpass filter based on half module substrate integrated wave guide structure of Fig. 1 embodiment.

Fig. 3 is a band of the dual-passband difference filter for the substrate integrated wave guide structure realized according to Fig. 1 embodiment The example of size indication.

Fig. 4 a is to add disturbance line of rabbet joint comparison diagram corresponding to dynamic line of rabbet joint differential mode is not scrambled, and Fig. 4 b is for the addition disturbance line of rabbet joint and not Scramble the dynamic corresponding comparison diagram of line of rabbet joint common mode.

Fig. 5 is two transmission zeros with x₁Trend chart.

Specific embodiment

In order to better understand the technical content of the present invention, special to lift specific embodiment and institute's accompanying drawings is cooperated to be described as follows.

As shown in Figure 1 with Figure 2, preferred embodiment according to the present invention, one kind being based on half module substrate integrated wave guide structure Differential bandpass filter comprising medium substrate 6, and be arranged in 6 surface of medium substrate upper surface metal layer 1 and under Surface metal-layer 7, medium substrate 6 have a horizontal axis L1 and vertical axis L2, the transmission direction of vertical axis L2 and signal It is identical.

It is logical that multiple perforative metallization are formed in the medium substrate 6, upper surface metal layer 1 and lower surface metal layer 7 Hole 2, plated-through hole 2 in 7 surface composition through-hole array of upper surface metal layer 1 and lower surface metal layer, the through-hole array, on Surface metal-layer 1 and lower surface metal layer 7 surround two and half mode resonant cavities, respectively the first half mode resonant cavities 31 and the second half Mode resonant cavity 32, the first half mode resonant cavities 31 and the second half mode resonant cavities 32 are symmetrical about horizontal axis L1, and the first half module is humorous Vibration chamber 31, which with the second half 32 adjoining positions of mode resonant cavity is formed with first and couples window and second, couples window.

Preferably, the diameter of the metal throuth hole 2 is 0.8mm, distance is 1.2mm between two adjacent through-holes.

Preferably, the medium substrate 6 uses RO5880 model, dielectric constant 2.2, with a thickness of 0.508mm.

Level on the edge of the upper surface metal layer 1 about the first coupling window or the second coupling window is right Position is claimed to be formed with the first disturbance line of rabbet joint 41 and the second disturbance line of rabbet joint 42.

Four feeder lines are arranged in the first half mode resonant cavity 31 and the aperture position of the second half 32 two sides of mode resonant cavity, respectively For the first feeder line 51, the second feeder line 52, third feeder line 53 and the 4th feeder line 54, transmitted for signal.

Preferably, refering to what is shown in Fig. 1, in the present embodiment, described first couples the length phase that window couples window with second Together.

Preferably, the first coupling window and the second coupling window are configured to symmetrical about vertical axis L2.

Preferably, the first disturbance line of rabbet joint 41 is identical with the structure of the second disturbance line of rabbet joint 42.

Present disclosure also relates to a kind of production method of the differential bandpass filter of aforementioned half module substrate integrated wave guide structure, Realize the following steps are included:

Surface metal-layer 1 and lower surface metal layer 7 are installed respectively on two surfaces of a medium substrate 6, it is preceding to give an account of The vertical axis L2 of matter substrate 6 is identical as the transmission direction of signal；

Multiple perforative metallization are formed on the medium substrate 6, upper surface metal layer 1 and 7 surface of lower surface metal layer Through-hole 2, by plated-through hole 2 in 7 surface composition through-hole array of upper surface metal layer 1 and lower surface metal layer, by described Through-hole array, upper surface metal layer 1 and lower surface metal layer 7 enclose packet and form two and half mode resonant cavities, and respectively the first half module is humorous Shake chamber 31 and the second half mode resonant cavities 32, wherein the first half mode resonant cavities 31 and the second half mode resonant cavities 32 be configured to about Horizontal axis L1 is symmetrical, and is formed with first with the second half 32 adjoining positions of mode resonant cavity in the first half mode resonant cavities 31 and couples Window and the second coupling window；

Level on the edge of the upper surface metal layer 1 about the first coupling window or the second coupling window Symmetric position forms the first disturbance line of rabbet joint 41 and the second disturbance line of rabbet joint 42；

Four feeder lines are arranged in aperture position in the first half mode resonant cavity 31 and the second half 32 two sides of mode resonant cavity, point Not Wei the first feeder line 51, the second feeder line 52, third feeder line 53 and the 4th feeder line 54, for signal transmit.

As previously mentioned, forming described two coupling windows in the following manner in this production method:

First coupling window is coupled into window with second and is arranged to identical length, and is symmetrical about vertical axis L2.

As previously mentioned, two transmission zeros can be obtained by the first disturbance line of rabbet joint 41 of addition and the second disturbance line of rabbet joint 42, In alternative embodiment, aforementioned production method is further comprising the steps of:

The size of described two line of rabbet joint 41,42 and/or the spacing of two line of rabbet joint 41,42 and half mode resonant cavity are adjusted, thus The corresponding frequency values of adjustment signal transmission zero.

With reference to the one of the dual-passband difference filter of the substrate integrated wave guide structure of Fig. 1 embodiment shown in Fig. 3 realization A example with size indication, in which: two and half mode resonant cavity width are w, length l₁.Two and half mode resonant cavity two sides four The width for coupling window is g₁, the coupling window width that the first half mode resonant cavities 31 are connected with the second half mode resonant cavities 32 is l₃。 The width of four feeder lines is w₃, the metal patch width of feeder line and respective mold half resonant cavity junction is g₂。

In order to improve the selectivity of differential bandpass filter, in the dielectric-slab the first half mode resonant cavity 31 and the second half module Connected coupling the window's position of resonant cavity 32 has etched the first disturbance line of rabbet joint 41 and the second disturbance line of rabbet joint 42 respectively, wherein first disturbs The dynamic line of rabbet joint 41 and the second disturbance 42 length of the line of rabbet joint, width are equal, respectively l₂And w, two disturbance line of rabbet joint are apart from right side metal The distance for changing through-hole is x₁., by etching the line of rabbet joint, a transmission zero can be respectively generated in the two sides of difference passband.Such as Fig. 4 a- 4b is etching disturbance line of rabbet joint comparison diagram corresponding to the disturbance difference of the line of rabbet joint is not etched.Secondly, by adjusting the position of the disturbance line of rabbet joint x₁Value, two transmission zeros have different variations, and first transmission zero is with x₁It varies less, and the second differential transfer zero point With x₁Increase and reduce, as shown in Figure 5.

To realize the differential bandpass filter based on half module substrate integrated wave guide structure, optimum-size parameter are as follows: l₁= 30 mm,l₂=3mm, l₃=5.9mm, w₁=8mm, w₂=2mm, w₃=1.6mm, g₁=3.7mm, g₂=2.5mm.

The centre frequency that the present invention measures gained difference passband is 8.65GHz, three dB bandwidth 720MHz, minimum insertion Loss is 2.5dB.Return loss is better than 16.5dB, and two transmission zeros are located at 6.76 and 10.7GHz, improves frequency selectivity. For common-mode response, measured signal inhibiting rate is better than 34.5dB in difference passband.10.5GHz frequency range is arrived 6.7 Interior, common mode inhibition is higher than 20dB.The filter proposed has good common mode inhibition capacity, is provided simultaneously with the small spy of size Point, this can be in the balance reception module for being widely used in microwave and millimeter wave high-performance, small size.

Although the present invention has been disclosed as a preferred embodiment, however, it is not to limit the invention.Skill belonging to the present invention Has usually intellectual in art field, without departing from the spirit and scope of the present invention, when can be used for a variety of modifications and variations.Cause This, the scope of protection of the present invention is defined by those of the claims.

Claims

1. A differential bandpass filter based on a half-mode substrate integrated waveguide structure, characterized in that it comprises a dielectric substrate (6), and an upper surface metal layer (1) and a lower surface disposed on the surface of the dielectric substrate (6) The metal layer (7), the dielectric substrate (6) has a horizontal axis (L1) and a vertical axis (L2), and the vertical axis (L2) is the same as the transmission direction of the signal, wherein:

A plurality of penetrating metallized through holes (2) are formed on the dielectric substrate (6), the upper surface metal layer (1) and the lower surface metal layer (7), and the metallized through holes (2) are in the upper surface metal layer (1) and the surface of the lower surface metal layer (7) form a through-hole array, and the through-hole array, the upper surface metal layer (1) and the lower surface metal layer (7) enclose two half-mode resonant cavities, which are the first The half-mode resonator (31) and the second half-mode resonator (32), the first half-mode resonator (31) and the second half-mode resonator (32) are symmetrical about the horizontal axis (L1), and the first half-mode resonator (31) and the second half-mode resonator (32) are A first coupling window (C1) and a second coupling window (C2) are formed at a position where the mode resonator (31) is adjacent to the second half-mode resonator (32);

A first disturbance slot line (41) and a second disturbance slot line are formed on the edge of the upper surface metal layer (1) at a horizontally symmetrical position with respect to the first coupling window (C1) or the second coupling window (C2) (42);

Four feeders are provided at the opening positions on both sides of the first half-mode resonant cavity (31) and the second half-mode resonant cavity (32), which are respectively a first feeder (51), a second feeder (52), and a third feeder (53) and a fourth feeder (54) for signal transmission;

The length of the first coupling window (C1) and the second coupling window (C2) are the same;

the first coupling window (C1) and the second coupling window (C2) are arranged to be symmetrical about the vertical axis (L2);

The structures of the first disturbance slot line (41) and the second disturbance slot line (42) are the same.

2. a manufacturing method of the differential bandpass filter based on half-mode substrate integrated waveguide structure as claimed in claim 1, is characterized in that, comprises the following steps:

The upper surface metal layer (1) and the lower surface metal layer (7) are respectively installed on two surfaces of a dielectric substrate (6), and the vertical axis (L2) of the aforementioned dielectric substrate (6) is the same as the transmission direction of the signal;

A plurality of penetrating metallized through holes (2) are formed on the surfaces of the dielectric substrate (6), the upper surface metal layer (1) and the lower surface metal layer (7), and through the metallized through holes (2), the upper surface metallization holes (2) are formed. The surface of the layer (1) and the lower surface metal layer (7) forms a through hole array, and two half-mode resonant cavities are formed by surrounding the through hole array, the upper surface metal layer (1) and the lower surface metal layer (7), are the first half-mode resonant cavity (31) and the second half-mode resonant cavity (32), respectively, wherein the first half-mode resonant cavity (31) and the second half-mode resonant cavity (32) are arranged about the horizontal axis ( L1) is symmetrical, and a first coupling window (C1) and a second coupling window (C2) are formed at the positions adjacent to the first half-mode resonator (31) and the second half-mode resonator (32);

Four feeders are provided at the opening positions on both sides of the first half-mode resonant cavity (31) and the second half-mode resonant cavity (32), which are the first feeder (51), the second feeder (52), the third a feeder (53) and a fourth feeder (54) for signal transmission;

The two coupling windows are formed as follows:

The first coupling window (C1) and the second coupling window (C2) are set to the same length, and are symmetrical about the vertical axis (L2);

Also includes the following steps:

Adjust the size of the two slot lines (41, 42) and/or the distance between the two slot lines (41, 42) and the half-mode resonant cavity, so as to adjust the frequency value corresponding to the zero point of signal transmission; by adding a first disturbance slot The line (41) and the second perturbation slot line (42) can obtain two transmission zero points, and the first perturbation slot line (41) and the second perturbation slot line (42) are symmetrical about the horizontal axis, while changing the position of the perturbation slot line The frequency value corresponding to the transmission zero can be adjusted accordingly.