Design Of C-Band RF Receiver Front-end

Active Electronic Scanning Array (AESA) will be widely used in the next generation of radar, communication and electronic warfare system, the system needs to apply in the airborne, space borne, balloon borne platform and so on, therefore the T/R modules must have a higher level of integration, lower cost and more functions. And the multi-functional phased array chip is a technical solution for next-generation T/R modules.This paper presents a C-band RF receiver front-end design based on 0.18μm RF CMOS process, this RF receiver front-end consists of a single-differential low noise amplifier (LNA), a quadrature down-conversion mixer and a RC polyphase filter. It can receive RF signals, implement frequency conversion and reject image signals. The single-differential low noise amplifier based on common-gate and common-source (CG-CS) structure can change a single-ended signal to a differential signal, a CG stage with capacitance cross coupling technology is cascaded in this CG-CS structure to provide a feed-forward path, which can enhance gain and reduce noise. A RLC resonant circuit is used as the load in order to attain high gain and linearity, the size of the resistance R can change Q value of this resonant circuit which is related to the fluctuation of the conversion gain. The quadrature down-conversion mixer is based on Gilbert double-balanced structure, the transconductance stage is shared by I/Q channels to reduce mismatches, the LC resonant circuit is used as the load of this Mixer so as to obtain high gain and high linearity, the resistance provides a negative feedback path to achieve high input linearity. A two stage polyphase filter is used to select intermediate frequency signals and reject image signals. This paper provides circuit design and layout design of the C-band RF receiver front-end. The pre-simulation and post-simulation have been completed considering of process and temperature. The post-simulation results show that under 3.3V power supply, the current consumption is 60.80mA, the conversion gain is 24.24dB, the noise figure (NF) is under 7.81dB, the output referenced 1dB compression point (OP1dB) is 8.34dBm, the input matching S11 is under -20.57dB and the image rejection ratio is more than 48.48dBc.The performance of the C-band RF receiver front-end meets design requirement well and it can be applied in C-band RF transceiver chip.