CN207165726U

CN207165726U - Super wide band microstrip bandpass filter

Info

Publication number: CN207165726U
Application number: CN201721048381.6U
Authority: CN
Inventors: 蔡超波; 宋树祥; 袁伟强; 王斌; 王宜瑜; 胡文灿
Original assignee: Guangxi Normal University
Current assignee: Guangxi Normal University
Priority date: 2017-08-21
Filing date: 2017-08-21
Publication date: 2018-03-30
Anticipated expiration: 2027-08-21

Abstract

The utility model discloses a kind of super wide band microstrip bandpass filter, the bandpass filter includes cascading formed low pass filter by 3 H-shaped defected microstrip structures, then respectively at low pass filter input, output port microstrip line on be subject to quarter-wave termination short-circuit resonant device.Relative bandwidth of the present utility model has reached 116%, 20dB high frequencies stopband reaches 7GHz, it is wider than the corresponding data of other prior arts a lot, size is also more other small, have the advantages that overall performance is good, compact-sized, insertion loss is small, stopband is wide, be highly suitable for the design of high density monolithic integrated microwave circuit.

Description

Super wide band microstrip bandpass filter

Technical field

It the utility model is related to communication device, and in particular to a kind of super wide band microstrip bandpass filter.

Background technology

For ultra-wide band filter as ultra wide band circuit and the indispensable device of system is established, its development is very fast.For Small design, low insertion loss, the wave filter of Wide stop bands, developer have carried out substantial amounts of research [1-6].Document [1] is public To open and realized bandpass filtering by the way of low pass filter and high-pass filter cascade, the wave filter Out-of-band rejection is preferable, but It is that its is complicated, size is larger, is not easy to design and integrates.Document [2-4] is loaded using minor matters and parallel coupled line structure Ultra-wide band filter is formed, its pass band insertion loss is small, and Stopband Performance is also preferable, but its size is larger.Document [5] describes logical The form for crossing open circuit in parallel and short-circuit minor matters line forms ultra-wide band filter, and this method is simple in construction, but its Out-of-band rejection is not Enough, stopband is narrower.

Utility model content

The utility model provides a kind of low pass filter by defected microstrip structure and cascades and form with short-circuit resonant device Ultra wide band bandpass filter.The utility model is made up of the higher cut-off frequency of ultra-wide band filter the low pass filter of DMS structures Rate, by loading short-circuit minor matters line, form the lower-cut-off frequency of wave filter, the relative bandwidth of preferred scheme of the present utility model Reached 116%, -20dB high frequencies stopband reaches 7GHz, it is wider than the corresponding data of other prior arts a lot, size also compared with It is small disclosed in other documents, have the advantages that overall performance is good, compact-sized, insertion loss is small, stopband is wide, be especially suitable for Design for high density monolithic integrated microwave circuit.

The utility model is cascaded by low pass filter and short-circuit minor matters line, low pass filter preferred cut-off frequency ω_c =10.6GHz, using DMS structures.DMS structures are to etch defect pattern on conventional microstrip line, by entering on the microstrip line Row cutting, the effective dielectric constant of microstrip line is changed, add the electrical length of microstrip line, so as to change the spy of microstrip line Property.Low pass filter is made up of 3 H-shaped DMS structures cascades, then respectively at low pass filter input, the micro-strip of output port It is subject to quarter-wave termination short-circuit resonant device on line.

Brief description of the drawings

Fig. 1 is H-shaped DMS microstrip structure figures.

Fig. 2 is the low-pass filter structure figure in the utility model.

Fig. 3 is structure chart of the present utility model.

Fig. 4 is S parameter simulation result of the present utility model and measured result comparison diagram.

Embodiment

The specific embodiment of an optimization is given below, to describe the technical solution of the utility model and acquisition in detail Beneficial effect.

As shown in Figure 1.L₁、W₁Respectively input, the length of output port microstrip line and width, L₂、W₂Respectively to be etched is micro- Length and width with line, L₃、W₃The length and width of the line of rabbet joint up and down of the H-shaped line of rabbet joint respectively etched, L₄、W₄The line of rabbet joint among respectively It is long and wide.It is big in 10.6GHz, resistance band to obtain cut-off frequency by the way of 3 DMS structures cascade for the utility model It is as shown in Figure 2 in 7GHz low pass filter, its structure.By the low pass filter and quarter-wave of 3 DMS structures cascades Terminal short circuit resonator cascade, particularly as be respectively input, output port 50 Ω microstrip lines on be subject to terminal short circuit resonance Device is so as to obtain super wide band microstrip bandpass filter, as shown in Figure 3.The utility model produces 2 zero at 0GHz and 13GHz Point, so as to obtain the lower-cut-off frequency of bandpass filter and upper cut-off frequency；2 limits are produced at 4GHz and 9GHz, The return loss of wave filter is improved, and then improves the insertion loss of wave filter, makes its value as small as possible.

Preferred scheme of the present utility model is given below, can maximize the effect of acquisition.

The length L of 2 line of rabbet joint up and down of first H-shaped defected microstrip structure in 3 H-shaped defected microstrip structures₃'= 2.3mm and width W₃'=0.4mm；The length L of the middle line of rabbet joint₄'=2.7mm and width W₄'=0.25mm.Second H-shaped The length L of 2 line of rabbet joint up and down of defected microstrip structure₃"=2.3mm and width W₃"=0.4mm；The length L of the middle line of rabbet joint₄″ =3.2mm and width W₄"=0.3mm.The length L of 2 line of rabbet joint up and down of 3rd H shape defected microstrip structure₃" '=2.3mm And width W₃" '=0.4mm；The length L of the middle line of rabbet joint₄" '=2.7mm and width W₄" '=0.25mm.Quarter-wave The length and width of terminal short circuit resonator is respectively 3.3mm and 0.2mm.

By ADS (advanced design system) software emulation, simulation result is as shown in figure 4, S21 is wave filter Insertion loss, S11 be wave filter return loss.It can be seen that the passband of bandpass filter provided by the utility model is 2.9~10.6GHz, relative bandwidth FBW are 116%, and the insertion loss in passband is less than 1dB, while by adding terminal short circuit Resonator produces a zero point at 13GHz, adds the resistance band of bandpass filter, frequency range of the stopband below -20dB For 12~19GHz, its width has reached 7GHz, while reduces the pass band insertion loss of bandpass filter.The bandpass filter Size is 13.7mm × 6.8mm, and the wave filter of design is tested using Agilent N5230C Network Analyzers, and parameter is as schemed Shown in 4.

Scheme comparison disclosed in test result and each document see the table below 1, and bandpass filter provided by the utility model- 20dB high frequency stopbands have 7GHz, also more other smaller than wide many disclosed in other documents, size.

The test result of table 1 and bibliography Comparative result

Note：- represent not refer to.

Bibliography：

[1]SU C F,QI X Q,YANG Z B.Design of UWB bandpass filter using highpass and dual-plane EBG lowpass filters[C]//Proceeding of the 2013 IEEE International Conference on Applied Superconductivity and Electromagnetic Devices (ASEMD).Piscataway,NJ:IEEE Press,2013:149-152.

[2]CHU Q X,TIAN X K.Design of UWB bandpass filter using stepped- impedance stub-loaded resonator[J].IEEE Microwave and Wireless Components Letters, 2010,20(9):501-503.

[3]FAN L,ZHAO Y J,QIN H B,et al.A UWB filter design based on stepped impedance resonator[C]//Proceeding of the 9th International Symposium on Antennas, Propagation and EM Theory (ISAPE) .Piscataway, NJ:IEEE Press,2010:974- 976.

[4]CHEN C P,TAKAHASHI J,IINUMA R,et al.Design of UWB filter with SIRs and parallel-coupled three lines[C]//Proceeding of the 2011 China-Japan Joint Microwave Conference.Piscataway,NJ:IEEE Press,2011:1-4.

[5] Huang Xiaodong, a kind of miniature ultra wide band microstrip bandpass filter [J] Chinese science and technologies opinion of Jin Xiuhua, Cheng Chong tigers Text, 2013 (10):955-958.

[6] Yang Hong, Chen Jing, Liu Yunlong, waiting a kind of, the ultra wide band bandpass filter based on multimode resonator designs [J] Electronic component and material, 2015 (6):61-65.

Claims

1. a kind of super wide band microstrip bandpass filter, including low pass filter, it is characterised in that：The low pass filter is by 3 H The cascade of shape defected microstrip structure is formed, then input respectively at low pass filter, be subject to four on the microstrip line of output port/ One wavelength terminal short circuit resonator.

2. super wide band microstrip bandpass filter according to claim 1, it is characterised in that：3 H-shaped defect micro-strip knot The length L ' of 2 line of rabbet joint up and down of first H-shaped defected microstrip structure in structure₃=2.3mm and width W '₃=0.4mm；In Between the line of rabbet joint length L '₄=2.7mm and width W '₄=0.25mm；2 line of rabbet joint up and down of second H-shaped defected microstrip structure Length L "₃=2.3mm and width W "₃=0.4mm；The length L " of the middle line of rabbet joint₄=3.2mm and width W "₄=0.3mm；The The length L " ' of 2 line of rabbet joint up and down of three H-shaped defected microstrip structures₃=2.3mm and width W " '₃=0.4mm；The middle line of rabbet joint Length L " '₄=2.7mm and width W " '₄=0.25mm；The length and width of quarter-wave termination short-circuit resonant device point Wei not 3.3mm and 0.2mm.