Fast frequency hopping achieved with SAW synthesizers

A wide variety of both military and commercial systems require high spectral purity, low noise, precise, rapid frequency-hopped signal sources, or synthesizers. Hopping speeds of less than a microsecond preclude the use of phase-locked loops. However, direct synthesizers can readily change frequency in a fraction of a microsecond. SAW filters are a logical choice for the filter banks which low-cost, compact, direct synthesizers require. A description is given of a two mixer switched SAW filterbank synthesizer. Attention is given to the source section, the switched SAW filterbank section, and a summary of the performance of the RADC synthesizer. A two mixer iterative synthesizer is also considered along with a four mixer modular iterative synthesizer.