Research Of Millimeter Wave Filter Based On Substrate Integrated Waveguide

With the advent of the 5G era,the competition for spectrum resources also extends to the millimeter wave(Millimeter wave)frequency band.The millimeter wave frequency band can not only provide wider spectrum resources,but also meet the high-speed and low-latency requirements of future communication systems.As a key component to ensure the communication quality of the entire millimeter wave communication system,the design of the millimeter wave filter has also become The current research hotspots.At present,the millimeter wave frequency band mainly studied by countries in the world is 24.5GHz?27.5GHz.In order to solve the high signal selection requirements of communication systems in this frequency band,there is an urgent need for new millimeter wave filters with simple structure,miniaturization,ultra-wideband,and low loss.Research and design.Substrate Integrated Waveguide(SIW)is a new type of planar waveguide structure,which has the characteristics of high quality factor and low loss,and is widely used in high-frequency communication systems.The main research contents of this paper are as follows:1.A new type of claw-shaped DGS structure was designed on the basis of the traditional dumbbell-shaped defective ground structure(DGS),which has a higher degree of design freedom.Finally,a SIW bandpass filter based on the claw-shaped DGS structure was designed by cascading two sets of new DGS structures.The center frequency is 26 GHz,the 3d B relative bandwidth reaches 26.9%,and the overall size is only 10 × 5mm,which can be seen.It has the characteristics of simple structure,miniaturization,ultra-wideband and so on.Then it was proposed to load a U-shaped electromagnetic band gap(EBG)structure next to the filter input and output microstrip line feed structure to increase the transmission zero point,thereby improving the out-of-band suppression capability of the above-mentioned filter.The final design was based on With the new DGS-EBG structure millimeter wave filter,the 30 d B squareness factor is improved from 1.64 to 1.34.2.Through the study of multi-mode resonance characteristics,it was proposed to use a rectangular dual-mode SIW resonator to design a millimeter wave filter with low loss and high performance.By introducing an improved Complementary Split Ring Resonator(CSRR)structure,a dual-mode SIW bandpass filter loaded with a new type of CSRR structure is designed.The center frequency is 25 GHz,the insertion loss is-0.5d B,and the return loss is Better than 20 d B,it can be seen that it has the characteristics of low loss and high performance.3.In order to obtain a high-performance,ultra-wideband millimeter wave filter,it was proposed that two single-mode resonators(TE101)were magnetically coupled with a rectangular dual-mode SIW resonator through a coupling window,and a fourth-order cavity is designed.The coupled SIW bandpass filter has a center frequency of 27 GHz,an insertion loss of-0.5d B,a return loss of better than 20 d B,and a relative bandwidth of20.2%.It can be seen that it has high performance and ultra-wideband characteristics.