Design Of LNA And Mixer For Dual-Band RF Front Ends

With the rapid development of wireless communication and the immense market, the correlative wireless IC solutions have been widely researched. Thereinto, the solution based on CMOS process is becoming a hot research field. As the key blocks of RF receiver, LNA and Mixer designed in CMOS process are paid more attention by the RFIC designers. This thesis designs the LNA and Mixer which apply to a zero-IF receiver using in WLAN (802.11a) and 3G(2.6GHz) in CMOS process.First, this thesis present a dual-band LNA improved on a existing structure following an active balun circuit. We use the power constraint simultaneous noise and input matching technology to do the theory analysis and performance optimization. The simulation results show the input impendence matching at the dual-band, 0.649-dB,0.778-dB noise figure , 14.98-dB,9.5-dB power gain at 2.6GHz and 5.2GHz respectively.As the Mixer block, we adopt the quadrature Gilbert structure based on the double balanced Gilbert Mixer. Simultaneously, we add the DC-offset correction circuit which includes a CMFB block and a DMFB block. The simulation result shows the addition of the DC-offset correction circuitry has reduced the simulated differential DC offset voltage to less than 5% of the uncorrected offset circuit. For the entire circuit, we utilize the degree of impedance matching between LNA and Mixer to realize the gain control of the RF frond-end circuitry. The power gain ranges are 42~52-dB and 24~51dB in t2.6GHz and 5.2GHzIn the end of this thesis, the whole circuit simulation results are given and the layout design are accomplished. Some advices for future work are also given.