Septmber 2005, Issue 182

Signal Generation Solution
Build an Inexpensive RF Signal Generator

NEXT STEPS

This was a fun and challenging project, but I feel like I’ve just seen the proverbial tip of the iceberg. I now want to evolve this design and continue exploring the process of working at these higher frequencies. I plan to control the LO and RF oscillators’ frequencies with phase-locked loops for better stability. I would like to use VCOs that operate at 5 V and have control voltages of up to 5 V to simplify the necessary power supplies. I’m going to look for a wider BW variable-gain amplifier in order to operate at higher frequencies. I would also like to add true RMS detection to the gain control loop for output level accuracy. Finally, I’ll probably add a full keypad interface to the microprocessor in an effort to create more flexibility when controlling the frequency and level.