Research And Design Of Miniaturized Filter For 5G Millimeter Wave Band Receiver

With the rapid development of wireless communication,5G communication technology is officially commercialized in 2019.The millimeter wave band has attracted more and more attention due to its outstanding advantages such as wide spectrum and light authorization.How to design and manufacture a small-sized,high-performance filter for 5G millimeter-wave receivers is the focus and difficulty of research.The filter is a very important device in the wireless communication system.The most important role of the filter is frequency selection.At the same time,the filter also plays an important role in suppressing the spurious frequency and improving the group delay of the system.5G millimeter-wave communication systems place higher requirements on the design of filters.This article focuses on 5G millimeter wave band receivers.Several band-pass filters are designed to work in the millimeter wave band and the intermediate frequency band.The main contents are as follows:The research analyzes the processes and applications of the thick-film integrated passive device process and the thin-film integrated passive device process,as well as their advantages.Based on these two processes and common PCB process modeling and simulation,a section of 50 ohm microstrip line and one-half wavelength microstrip line resonators are simulated,compared between the two processes and common PCB processes.It is concluded that the thin-film integrated passive device process can provide a smaller size.Based on the thin film integrated passive device process,the resonance characteristics of the microstrip line split ring resonator and the folded grid branch resonator based on the gallium arsenide substrate material were analyzed.Based on these two resonators,two band-pass filters operating at 26 GHz are designed and simulated.The size of the microstrip line split ring bandpass filter is 1.8mm ~* 1.8mm,the minimum insertion loss in the passband is-2.7d B,and the return loss in the passband is below-20 d B.There are two transmission zeros at 23.17 GHz and 29.24 GHz on both sides of the passband,which effectively improves the out-of-band suppression characteristics.The size of the folded grid branch bandpass filter is 0.9mm ~* 1mm,the minimum insertion loss in the passband is-5d B,and the return loss in the passband is below-20 d B.There are two transmission zeros at 23.6GHz and 29.3GHz on both sides of the passband,which greatly improves the out-of-band suppression characteristics.Based on the thin-film integrated passive device process,a lumped parameter filter with a working frequency of 2.5GHz was designed and simulated.The filter has a working bandwidth of 300 MHz and an overall size of 0.9mm ~* 1.382 mm.The insertion loss in the passband is-4.3d B,the return loss in the passband is below-16 d B.At the frequency of 1.7GHz and 3.35 GHz,each has a transmission zero,which greatly improves the out-of-band suppression performance.Simulation results show that the designed filter meets the design requirements.