CN106898848B

CN106898848B - A kind of ultra-wide stop-band low-pass filter of H-type open circuit minor matters combination palisading type defect ground structure

Info

Publication number: CN106898848B
Application number: CN201710190221.3A
Authority: CN
Inventors: 于映; 李芙蓉
Original assignee: Nanjing Post and Telecommunication University
Current assignee: Nanjing Post and Telecommunication University
Priority date: 2017-03-28
Filing date: 2017-03-28
Publication date: 2019-01-18
Anticipated expiration: 2037-03-28
Also published as: CN106898848A

Abstract

The invention relates to an ultra-wide stop-band low-pass filter with an H-type open-circuit branch combined with a fence-type defect structure, which can realize the ultra-wide stop-band low-pass filter required by a radio frequency system, and has a wider filter than the traditional DGS filter. The stop band has a good roll-off degree, and in practical applications, based on this design, a microwave filter with a small volume can be manufactured, thereby improving the integration of radio frequency devices and systems.

Description

A kind of ultra-wide stopband low pass filtered of H-type open circuit minor matters combination palisading type defect ground structure Wave device

Technical field

The present invention relates to a kind of ultra-wide stop-band low-pass filters of H-type open circuit minor matters combination palisading type defect ground structure, belong to In Electromagnetic Field and Microwave Technology field.

Background technique

In wireless telecommunication system, radio-frequency devices of the microwave filter as a kind of key with frequency selector, The superiority and inferiority of performance decides the quality of whole system communication quality, can also restrict the hair of wireless telecommunication system to a certain extent Exhibition.Therefore, high-performance, miniaturization the research of filter be all a research emphasis all the time.Lacking with band gap properties It falls into ground structure (DGS) and possesses huge application value in terms of improving performance of filter, attracted the wide of domestic and international researcher General concern.There are many unique performances, such as single pole and low pass characteristic just because of DGS, Slow-wave effect has higher feature Impedance etc., so that the research to DGS becomes a new research hotspot in microwave circuits.

In recent years, it is emerged one after another using the document of defect ground structure design low-pass filter, however traditional dumbbell structure Defect (DGS) intermediate zone decline it is more gentle, selectivity it is bad, the overall volume of microwave device is also bigger, DGS structure list The low-pass filter stopband that the period simple cascade of member is constituted is not wide enough, cannot effectively inhibit higher harmonics, and simple The area that cascade will lead to filter is larger, and uses multilayer technique, there are processing difficulties.

Summary of the invention

Technical problem to be solved by the invention is to provide a kind of using H-shaped open circuit minor matters, not by cascade lateral dimension Same palisading type defect ground structure, the H-type open circuit minor matters that can be realized ultra-wide stop-band low-pass filter needed for radio frequency system combine The ultra-wide stop-band low-pass filter of palisading type defect ground structure.

In order to solve the above-mentioned technical problem the present invention uses following technical scheme: the present invention devises a kind of H-type open circuit branch Nodule closes the ultra-wide stop-band low-pass filter of palisading type defect ground structure, including medium substrate, ground metal layer, straight line shaped microstrip Transmission line, at least three open circuit minor matters lines and at least two groups palisading type defect ground structure；Wherein, ground metal layer covering is set to The back side of medium substrate, linear microstrip transmission line are set on the front of medium substrate, and the two of linear microstrip transmission line End connects with the front edge of medium substrate respectively；Each open circuit minor matters line is respectively arranged on the front of medium substrate, straight line Shaped microstrip transmission line is successively connected with the midpoint of each open circuit minor matters line, and each open circuit minor matters line is transmitted with straight line shaped microstrip respectively Line is perpendicular, and default spacing is kept between adjacent open circuit minor matters line；The quantity of palisading type defect ground structure is open circuit minor matters line Quantity subtract one, each group palisading type defect ground structure respectively between each adjacent open circuit minor matters line gap correspond, each group Palisading type defect ground structure includes respectively two sub- palisading type ground structures and a connecting line construction, is tied to each group palisading type defect Two sub- palisading type ground structures in structure are respectively positioned in ground metal layer with corresponding connecting line construction, and by for ground connection gold The etching for belonging to layer is realized；Using the direction perpendicular to surface where medium substrate as projecting direction is referred to, in reference projecting direction On, the projected position of two sub- palisading type ground structures is located at corresponding adjacent open circuit minor matters in each group palisading type defect ground structure Between line in gap, the two sides of linear microstrip transmission line, and two sub- palisading types in each group palisading type defect ground structure Structure on reference projecting direction using linear microstrip transmission line as axis axisymmetricly, it is each and on reference projecting direction The edge of sub- palisading type ground structure respectively the edge of linear microstrip transmission line corresponding with around it, open a way minor matters line edge It is connected to each other；Connecting line construction in each group palisading type defect ground structure is located between corresponding two sub- palisading type ground structures, and line The both ends of structure are connected to each other with corresponding two sub- palisading type ground structures respectively, and straight line where connecting line construction and straight line shaped microstrip transmit Straight line where line is perpendicular.

As a preferred technical solution of the present invention: spacing between each adjacent open circuit minor matters line, along linear Straight line where microstrip transmission line is incremented by successively.

As a preferred technical solution of the present invention: in each open circuit minor matters line, being passed along the straight line shaped microstrip In thread transferring direction, the width of two open circuit minor matters lines of head and the tail is respectively less than the width of intermediate any one open circuit minor matters line.

As a preferred technical solution of the present invention: in each open circuit minor matters line, being passed along the straight line shaped microstrip In thread transferring direction, the width of two open circuit minor matters lines of head and the tail is equal to each other, and the width of intermediate each open circuit minor matters line is equal to each other.

As a preferred technical solution of the present invention: the quantity of the open circuit minor matters line is four.

A kind of ultra-wide stop-band low-pass filter of H-type open circuit minor matters combination palisading type defect ground structure of the present invention uses Above technical scheme is compared with the prior art, the H-type open circuit minor matters combination palisading type that the present invention designs is had following technical effect that The ultra-wide stop-band low-pass filter of defect ground structure, can be realized ultra-wide stop-band low-pass filter needed for radio frequency system, compared to biography DGS filter of uniting has broader stopband, has preferable degree of roll-offing, and in practical application, based on this design, can manufacture Microwave filter small in size out, to improve the integrated level of radio-frequency devices and system.

Detailed description of the invention

Fig. 1 is the ultra-wide stop-band low-pass filter of the open circuit minor matters combination palisading type defect ground structure of H-type designed by the present invention Front schematic view；

Fig. 2 is the ultra-wide stop-band low-pass filter of the open circuit minor matters combination palisading type defect ground structure of H-type designed by the present invention Schematic rear view.

Wherein, 1. medium substrate, 2. ground metal layers, 3. linear microstrip transmission lines, 4. open circuit minor matters lines, 5. palisading types Defect ground structure, 6. sub- palisading type ground structures, 7. connecting line constructions

Specific embodiment

Specific embodiments of the present invention will be described in further detail with reference to the accompanying drawings of the specification.

As depicted in figs. 1 and 2, the present invention devises a kind of ultra-wide of H-type open circuit minor matters combination palisading type defect ground structure Stop-band low-pass filter, in practical applications, specifically include medium substrate 1, ground metal layer 2, linear microstrip transmission line 3, At least three open circuit minor matters lines 4 and at least two groups palisading type defect ground structure 5；Wherein, the covering of ground metal layer 2 is set to medium The back side of substrate 1, linear microstrip transmission line 3 are set on the front of medium substrate 1, and the two of linear microstrip transmission line 3 End connects with the front edge of medium substrate 1 respectively；Each open circuit minor matters line 4 is respectively arranged on the front of medium substrate 1, directly Linear microstrip transmission line 3 is successively connected with the midpoint of each open circuit minor matters line 4, and each open circuit minor matters line 4 is micro- with linear respectively Band transmission line 3 is perpendicular, and default spacing is kept between adjacent open circuit minor matters line 4；The quantity of palisading type defect ground structure 5 is to open The quantity of road minor matters line 4 subtracts one, the gap one between each adjacent open circuit minor matters line 4 respectively of each group palisading type defect ground structure 5 One is corresponding, and each group palisading type defect ground structure 5 includes two sub- palisading type ground structures 6 and a connecting line construction 7, each group respectively Two sub- palisading type ground structures 6 in palisading type defect ground structure 5 are respectively positioned in ground metal layer 2 with corresponding connecting line construction 7, And it is realized by the etching for ground metal layer 2；Using the direction perpendicular to 1 place surface of medium substrate as with reference to projection Direction, on reference projecting direction, the projected position of two sub- palisading type ground structures 6 point in each group palisading type defect ground structure 5 It Wei Yu not correspond between adjacent open circuit minor matters line 4 in gap, the two sides of linear microstrip transmission line 3, and each group palisading type defect It is in axis pair that two sub- palisading type ground structures 6 in ground structure 5, which are axis with linear microstrip transmission line 3 on reference projecting direction, Claim, and on reference projecting direction, the edge of each sub- palisading type ground structure 6 straight line shaped microstrip corresponding with around it respectively The edge of transmission line 3, the edge of open circuit minor matters line 4 are connected to each other；Connecting line construction 7 in each group palisading type defect ground structure 5 is located at Between corresponding two sub- palisading type ground structures 6, and the both ends of connecting line construction 7 respectively with corresponding two sub- 6 phases of palisading type ground structure Docking, 7 place straight line of connecting line construction and 3 place straight line of linear microstrip transmission line are perpendicular.

It on the basis of above-mentioned designed technical solution, in actual application, is specifically designed as follows, for opening The quantity of road minor matters line 4, is set as four；Spacing between each adjacent open circuit minor matters line 4, along 3 institute of linear microstrip transmission line It is incremented by successively in straight line；In each open circuit minor matters line 4, along 3 direction of linear microstrip transmission line, two open circuit branches of head and the tail The width of nodel line 4 is equal to each other, and the width of intermediate two open circuits minor matters line 4 is equal to each other, and two open circuit minor matters lines 4 of head and the tail Width be respectively less than the width of intermediate any one open circuit minor matters line 4.

The present invention devises a kind of ultra-wide stop-band low-pass filter of H-type open circuit minor matters combination palisading type defect ground structure, In practical applications, as depicted in figs. 1 and 2, each group palisading type defect ground structure 5 respectively includes two sub- palisading type ground structures 6 With a connecting line construction 7, specifically, each sub- palisading type ground structure 6 is respectively by lateral etching region and longitudinal etch areas Composition, each group palisading type defect ground structure 5 can be with Approximate Equivalents for a simple parallel LC resonance circuit, and L and C indicate fence The inductance and capacitor of type defect ground structure 5 itself in each group palisading type defect ground structure 5, are located at the transmission of straight line shaped microstrip The area of the sub- palisading type ground structure 6 of two of about 3 line is equivalent to inductance, value and transverse direction in two sub- palisading type ground structures 6 The number and lateral etching peak width of etch areas are directly proportional；The connecting line construction 7 of two sub- palisading type ground structures 6 of centre connection It can be then equivalent to a capacitor, size and the width of connecting line construction 7 are inversely proportional.The physics ruler of each group palisading type defect ground structure 5 Very little variation will affect the frequency of fadings of linear microstrip transmission line 3, can be by appropriate in order to realize that required with hinders characteristic The length and number in the lateral etching region of adjusting 5 neutron palisading type ground structure 6 of each group palisading type defect ground structure or longitudinal direction The size of etching width obtains required resonance frequency, i.e., the length in lateral etching region subtracts in group palisading type ground structure 6 When small or number reduces, frequency of fadings can increase therewith；Longitudinal etching in lateral etching region in sub- palisading type ground structure 6 When width increases, frequency of fadings can reduce therewith.

In practical application, the specific width for designing linear microstrip transmission line 3 is 1.8mm, the length of length and medium substrate 1 Spend it is identical, to obtain 50 ohm of characteristic impedance；The open circuit minor matters line 4 at 5 both ends of each group palisading type defect ground structure is loaded, is In order to enhance the coupled capacitor between linear microstrip transmission line 3 and each group palisading type defect ground structure 5, to further expand The bandwidth of rejection of each group palisading type defect ground structure 5.

The present invention devises a kind of ultra-wide stop-band low-pass filter of H-type open circuit minor matters combination palisading type defect ground structure, Microelectronic technique, laser technology or printed circuit technology can be used in manufacturing process.Wherein, ground metal layer 2, linear Microstrip transmission line 3, at least three open circuit minor matters lines 4 and at least two groups palisading type defect ground structure 5, it is all good by electric conductivity Conductor material is constituted；Medium substrate 1 can use dielectric constant for 3.55, and thickness of dielectric layers is the two-sided deposited copper sheet of 0.8mm (Rogers RO4003)。

To sum up, the ultra-wide stop-band low-pass filter of the open circuit of H-type designed by present invention minor matters combination palisading type defect ground structure, Can be realized ultra-wide stop-band low-pass filter needed for radio frequency system, compared to tradition DGS filter have broader stopband, with compared with Good degree of roll-offing, and in practical application, based on this design, microwave filter small in size can be produced, is penetrated to improve The integrated level of frequency device and system.

Embodiments of the present invention are explained in detail above in conjunction with attached drawing, but the present invention is not limited to above-mentioned implementations Mode within the knowledge of a person skilled in the art can also be without departing from the purpose of the present invention It makes a variety of changes.

Claims

1. An ultra-wide stopband low-pass filter with an H-type open-circuit branch combined with a fence-type defect structure, characterized in that: it comprises a dielectric substrate (1), a ground metal layer (2), a linear microstrip transmission line (3) , at least three open-circuit branch lines (4) and at least two sets of barrier-type defect ground structures (5); wherein, the ground metal layer (2) is arranged to cover the back of the dielectric substrate (1), and the linear microstrip transmission line (3) is arranged on the front surface of the dielectric substrate (1), and the two ends of the linear microstrip transmission line (3) are respectively connected with the front edge of the dielectric substrate (1); the open branch lines (4) are respectively arranged on the dielectric substrate (1) ), the linear microstrip transmission line (3) is connected to the midpoint of each open branch line (4) in turn, and each open branch line (4) is respectively perpendicular to the linear microstrip transmission line (3), and A preset distance is maintained between adjacent open-circuit branch lines (4); the number of barrier-type defected structures (5) is the number of open-circuit branch lines (4) minus one, and each group of barrier-type defected structures (5) is respectively associated with each group. The gaps between adjacent open-circuit branch lines (4) are in one-to-one correspondence, and each group of barrier-type defective ground structures (5) respectively includes two sub-barrier-type ground structures (6) and one connecting line structure (7). The two sub-barrier-type ground structures (6) and the corresponding connection structures (7) in the type defect ground structure (5) are both located on the ground metal layer (2), and both are etched for the ground metal layer (2) Realization; taking the direction perpendicular to the surface of the dielectric substrate (1) as the reference projection direction, in the reference projection direction, the projection positions of the two sub-barrier-type ground structures (6) in each group of barrier-type defect ground structures (5) are respectively located at Corresponding to both sides of the linear microstrip transmission line (3) in the gap between adjacent open branch lines (4), and two sub-barrier-type ground structures (6) in each group of barrier-type defect ground structures (5), refer to In the projection direction, the linear microstrip transmission line (3) is taken as the axis to be axially symmetrical, and in the reference projection direction, the edges of each sub-fence type ground structure (6) respectively correspond to the surrounding of the linear microstrip transmission line (3). The edges and the edges of the open-circuit branch lines (4) are connected to each other; the connecting line structures (7) in each group of fence-type defect ground structures (5) are located between the corresponding two sub-fence-type ground structures (6), and the connecting line structures ( The two ends of 7) are respectively opposite to the corresponding two sub-fence type ground structures (6), and the straight line where the connecting structure (7) is located is perpendicular to the straight line where the linear microstrip transmission line (3) is located.

2. The ultra-wide stop-band low-pass filter of a H-type open-circuit branch combined with a fence-type defect structure according to claim 1, characterized in that: the spacing between the adjacent open-circuit branch lines (4), along the The straight lines where the linear microstrip transmission line (3) is located are successively increased.

3. The ultra-wide stop-band low-pass filter of the H-type open-circuit branch combined with a fence-type defect structure according to claim 1 or 2, characterized in that: in each open-circuit branch line (4), along the In the direction of the linear microstrip transmission line (3), the widths of the two open branch lines (4) at the beginning and the end are both smaller than the width of any one of the open branch lines (4) in the middle.

4. The ultra-wide stop-band low-pass filter with an H-type open-circuit branch combined with a fence-type defect structure according to claim 3, characterized in that: in each open-circuit branch line (4), along the straight line In the direction of the microstrip transmission line (3), the widths of the two open branch lines (4) at the beginning and the end are equal to each other, and the widths of the middle open branch lines (4) are equal to each other.

5 . The ultra-wide stopband low-pass filter with an H-type open-circuit branch combined with a fence-type defect structure according to claim 4 , wherein the number of the open-circuit branch lines ( 4 ) is four. 6 .