Experimental results for a Successive Detection Log Video Amplifier in a single-chip frequency synthesized radio frequency spectrum analyzer

The scarcity of available frequency spectrum continues to motivate the development of new radio systems capable of adapting to local conditions. One approach to identifying available frequency spectrum is to employ an on-chip radio-frequency spectrum analyzer. In particular, the present article addresses the design of an experimental successive detection log video amplifier (SDLVA) to generate logarithmic output in a frequency-synthesized single-chip spectrum analyzer. The SDLVA design includes feedback compensation for DC offset error, and is tailored to accommodate the zero-IF architecture of the spectrum analyzer without the need for large off-chip capacitors. The SDLVA was designed and fabricated in 0.5 micron CMOS. Experimental results for the SDLVA are presented showing approximately 40 dB dynamic range. Results are also given for the overall spectrum analyzer integrated circuit showing SDLVA operation for a 200 MHz spectral sweep.