Research On Q-band Millimeter Wave Front-end Systems

With the explosive growth of the mobile Internet industry,communication systems with larger capacity and higher speed are urgently needed to support various emerging application scenarios in the future.Existing low-frequency spectrum resources are increasingly scarce,and millimeter wave frequency bands are favored by researchers for their rich spectrum resources to be developed and larger bandwidth.In order to accelerate the research process of millimeter wave bands in China,the China Wireless Personal Area Network Standardization Working Group formulated the Q-LINKPAN ultra-high-speed near-distance wireless communication standard which works at 40?50 GHz in 2010,and the short-range communication standard Q-LINKPAN-S evolved into the IEEE 802.11 aj standard.In this thesis,the Q-band millimeter wave transceiver front-end system is studied pointing at IEEE 802.11 aj communication standard.In this thesis,high-performance filters commonly used in front-end systems are first studied,including cross-coupled filters and DGS filters.At the same time,based on the integrated waveguide structure of the substrate,three types of SIW filters are designed,which are SIW dual-mode cavity filter,oversized SIW cavity filter and SIW-DGS filter.The above three filters are fabricated and measured and the measured and simulated results are basically consistent.Among them,the SIW-DGS filter can be used for the design of the LO module.Then the local oscillator(LO)module is designed according to the requirements of the system requirement,including two LO sub-links.The first LO is 10 GHz point frequency signal,and the second local oscillator is 29.3?35.4 GHz continuous signal.The output power of the first LO link is?8.34 dBm,and the phase noise is less than-90 dBc/Hz at 1kHz.The phase noise of the second LO link at 33 GHz is less than-80 dBc/Hz@1kHz,and the output power is about 3 dBm.Finally,the Q-band millimeter wave front-end system is designed and processed.The designed front-end system operates at 42.3?48.4 GHz and uses a three-frequency superheterodyne architecture.The output interface of the system selects the SIW interconnect structure,which can conveniently connect the antenna and test instruments.The test results show that the transmission channel gain is 38.15 dB,the output 1dB compression point is 11.5 d Bm,and the gain flatness is less than or equal to 2.5 dB;the receiving channel gain is 21.4 dB,the output 1d B compression point is-6.5 dBm.The EVM of the transmission channel and the receiving channel were measured,indicating that the system has good performance.