Low cost microwave X-band generator

A low cost microwave X-band generator for educational purposes was designed and built. Its simple construction and user´s interface makes it suitable for student laboratory. The generator is based on single frequency conversion concept. It uses a digitally tunable PLL chip for intermediate frequency generation and active frequency multiplier for frequency conversion. The generator covers 9,7 - 11 GHz part of X frequency band. The frequency tuning may also be done automatically in a slow frequency sweep mode, which saves a lot of manual work. The output signal is amplitude modulated in order to match with VSWR meters used in microwave laboratory. The signal level is stabilized by the automatic gain control unit comprising a dedicated MCU, digitally controlled attenuator and power detector, which reduces power fluctuations over whole frequency band.