Abstract: Signal converter systems are provided with N analog-to-digital converters that respectively respond to N interleaved clock signals which have a common clock frequency and are further provided with a filter network that processes the converters' output digital sequences with a selected filter passband a filter passband that is contained within a single one of Nyquist zones whose widths are one half of the clock frequency and that is positioned to pass information contained in the analog signal. In a system embodiment, the filter network comprises a symmetric systolic finite impulse response filter arranged to define N input ports for reception of the digital sequences.

Abstract: A chirp direct digital synthesizer is formed with a phase and frequency tracker circuit to provide both enhanced resolution and reduced power consumption. The phase and frequency tracker circuit operates at a sub-synchronous clock rate and provides periodic phase and frequency correction data to the direct digital synthesizer. The phase and frequency tracker circuit is suitable for both continuous wave and chirp direct digital synthesizer operation.