Research And Design Of The RF Analog Front-end Based On L-Band Receiver

RF front-end receiver is the first stage circuit of the L-band radar receiver system,it is an important part which affect the performance of the whole receiver directly.In different applications,the design of RF front-end of L-band radar receiver has a different emphasis to be considered.The research of the receiver rf front-end circuit is a focus in various agencies, which had invested a lot of manpower and resources on the RF front-end of receiver circuit.In this paper, we compared the main receiver solution in the current. On the basis of analysis of the receiver’s major works and technical indicators, we selected the fittable receiver structure to meet the requirements combined with the actual requirements of this topic. And we described the circuit design of the receiver front-end at all levels, and analysis the various devices throughout the RF front-end link in detail. On this basis, we designed the L-band radar receiver RF front-end circuit, which is widely applied to1.85GHz～1.95GHz.In the design,we choose a low noise LNA transistor, which adopted the minimum noise input matching and the maximum power output matching,then realized the design of this band low noise amplifier. In the case of guaranteeing its gain, it’s reduces noise factor in the before level in the greatest degree; using discrete LC devices,and build their own RF Mirror suppression filter and the band-pass filter;we use the RF circuit simulation software ADS of Agilent company to simulate the RF mirror suppression filter, band-pass filtering and the low-noise amplifier circuit. From the simulation results, we can see that circuit performance indicators meet the design requirements. And then combined with the overall demand, we choose the proper rf amplifier, mixer, controllable gain amplifier chip to realize the function of frequency conversion control and dynamic range.