Design Of 5G Millimeter-wave Bandpass Filter And Voltage-controlled Oscillator

With the increasing demand of users for high-speed and low-latency communication technologies,5G millimeter-wave has become a research hotspot leading a new round of technological breakthroughs in the field of wireless communication.Filters and oscillators,as key modules in 5G millimeter-wave circuits,provide good frequency selection characteristics and local oscillator signals for high-performance transceiver systems.In-depth study of 5G millimeter-wave filters and oscillators will be of great significance for improving the transmission quality of communication systems.Based on China’s 5G millimeter-wave frequency band(24.25～27.5GHz /37～42.5GHz),this paper studies and designs high-selectivity low-insertion loss bandpass filters and dual-band wide-tuning range low-phase noise voltage-controlled oscillators applied to 5G communication technology.The research work and innovation are as follows:(1)Aiming at the asymmetry problem of even-order Chebyshev polynomials,an improved symmetrical even-order Chebyshev polynomial is adopted to solve the problem of unequal input and output impedance caused by the asymmetry of even-order polynomials.Compared with low-order odd-order polynomials,it has better frequency selectivity.Based on this polynomial,the symmetrical sixth-order low-pass prototype component values are given,and the substrate integrated waveguide bandpass filters with window structure and EBG structure are designed.The proposed filters are all designed and processed by Rogers 5880 PCB technology,and their passband ranges are 36.83～42.82 GHz and 37.06～42.53 GHz respectively.The measured passband range of the substrate integrated waveguide bandpass filter with window structure is 37.61～42.98 GHz,which verifies the feasibility of the symmetrical even-order filter design.(2)Aiming at the problem of reconfigurable frequency of 5G millimeter-wave frequency source,a dual-band voltage-controlled oscillator based on transformer load switched inductor is proposed.The oscillator uses switched inductor to achieve dual-band switching,so that a single frequency source integrates two sets of millimeter-wave communication frequency bands without increasing additional circuit area and power consumption.Based on GF65 nm CMOS process design,the tuning range covers 24.15～28.68 GHz and 35.50～44.98 GHz,and the phase noise range at1 MHz frequency offset is-103.39～-96.83 d Bc/Hz and-98.76～-96.09 d Bc/Hz.(3)Aiming at the quadrature accuracy of the quadrature frequency source,a quadrature dual-band voltage-controlled oscillator based on transformer load switch inductance and in-phase injection coupling technology is proposed.The oscillator uses in-phase injection coupling to improve the quadrature accuracy,so that a single frequency source can output quadrature signals on the basis of integrating two sets of millimeter-wave communication frequency bands.Based on GF65 nm CMOS process design,the tuning range covers 24.02～28.29 GHz and 35.22～44.14 GHz,and the phase noise range at 1MHz frequency offset is-100.4～-96.7 d Bc/Hz and-95.5～-94.2d Bc/Hz.The phase error of the quadrature signal is 1.69°.