A Novel Design of Direct Coupled and Small Volume Filter for 5G Network

The design theory of the filter is introduced. Based on the theoretical calculation and analysis, a 5G system cavity filter is designed by using the RF/microwave simulation software HFSS. The relationship between the length of the resonant rod and the frequency, the relationship between the spacing of the resonant rod and the coupling coefficient, and the influence of the input and output ports on the external Q value are analyzed. The overall filter is simulated and optimized. The results show that, the volume of the filter is 52^x8^x12mm, in the pass-band (3.4 GHz~3.5 GHz), the insertion loss is less than 0.3dB; the return loss is more than 29dB, which is far better than the indicators of similar devices. When used in 5G communication system, it can improve the noise figure of the system, the communication distance and capacity, the stability of the communication system, and the experience of 5G users.