Digital radio frequency memory utilizing time interleaved analog to digital converters and time interleaved digital to analog converters

摘要

A digital radio frequency memory (DRFM) comprises a plurality of time interleaved analog to digital converters (ADCs) in cooperation with a plurality of time interleaved digital to analog converters (DACs) to provide an effective sampling rate which may be greater than the clock rate of the system. A higher sampling rate at the ADC increases instantaneous bandwidth, while a higher sampling rate at the DAC improves spectral purity. The ADCs and DACs are time interleaved by supplying a clock signal to each ADC/DAC which is skewed with respect to the previous and subsequent skewed signal. In order to process the higher effective sampling rate, a pre-computation of DAC values for each high rate sample is performed by an SDAC algorithm that pipelines the calculations of the processed sample values provided to the DAC. A DAC bias correction is provided to adjust for drift in the DACs.

主权项

1. A method of pre-calculating an input to a digital to analog converter (DAC) in a digital radio frequency memory (DRFM), the method comprising:
receiving a plurality of digital samples representative of a received RF waveform; determining a previous DAC value from said plurality of digital samples; computing a difference between a current digital sample and a previous digital sample; and adding said computed difference to said previous DAC input to calculate a new DAC input value.