Frequency Measurement Device with Reconfigurable Bandwidth and Resolution

This letter presents a low-cost and compact reconfigurable frequency measurement circuit able to reconfigure bandwidth and resolution, the design uses a varactor loaded phase shifter, a reference delay line, and power divider/combiner to form a 2-bit frequency discriminator with four states for frequency measurement. The reconfigurable discriminator has four bandwidth states of 0.5, 0.9, 1.3, and 1.7 GHz, with uniform subband resolution of 125, 225, 325, and 525 MHz, for each bandwidth state of operation, respectively.