Abstract
RF circuit GRF-3100 experimental system, the operating frequency of 800MHz，is divided into RF transmitter and RF receiver. Mixer which is the frequency conversion component is a key part of RF system. Each wireless communication systems always use over a mixer. Its performance will directly impact the performance of the whole system. Mixers model is composed of Multiplier and band-pass filter, and the main technical indicators of mixers are Conversion Gain, Isolation, Spurious Signal, 1dB Compression Level ，Intermodiation Distortion, Noise Figure and so on. The design of Dual Gate Mixer and transistor mixer is investigated and their performances are analyzed, which according to RF circuit experimental system GRF-3100 technical manual. In addition, this paper describes the entire process of the circuit design: circuit analysis, circuit diagram and PCB layout design, the actual circuit welding, debugging and performance testing. Finally, the paper also introduces the relative knowledge of the Protel DXP software, Surface Mounting Technology (SMT) and the spectrum analyzer.
Keywords: radio frequency system; dual gate mixer；transistors mixers
