A front-end of FMCW anticollision radar

The design and performance of a low cost X-band front-end of an FMCW anticollision radar which mainly consists of VCO, buffer, circulator and mixer is described in this paper. It operates at 9 GHz with over 300 MHz linear tuning range. The excellent GaAs MESFET voltage controlled oscillator has a good balance between the high output power and wide tuning range. A GaAs FET balanced resistive mixer is used in this circuit which provides the low intermodulation and low 1/f noise even at the very low IF (to tens of Hz). All of these features are very suitable for the application of this kind of radar.