摘要 |
A quadrature bandpass-sampling analog-to-digital demodulator (QBS-ADD) is provided. A radio frequency (RF) signal is received by a junction summer, which subtracts an in-phase feedback signal and a quadrature feedback signal from the RF signal to produce an error signal. The error signal is then bandpassed and amplified by the RF bandpass filter/amplifier. The amplified signal is bandpass-sampled by two low-resolution analog-to-digital converters clocking in quadrature, and is demodulated and converted into a digital in-phase signal and a digital quadrature signal. The down converted in-phase and quadrature signals are multiplied with two quadrature clocks. The results are converted to two analog signals and fed back to the RF input at the junction summer.
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