| 摘要 |
An N-bit analog to biphase-encoded analog-to digital converter, which comprises (1) a biphase amplitude modulator responsive to an analog signal and a microwave pump carrier frequency fc for deriving a biphase-encoded carrier signal having a phase value determined by the current polarity of the analog signal and a peak amplitude determined by the current magnitude of the analog signal, and (2) an ordinally-arranged group of comparators. The modulator and the comparators, in order, derive fixed-amplitude, biphase-encoded output signals, each having a phase value indicative of a separate one of the most significant bit (MSB) to the Nth MSB in response to a biphase-encoded, modulated-carrier signal and the pump carrier frequency fc applied as inputs to each of the ordinally-arranged comparators. A corresponding ordinally-arranged group of sample and hold circuits, each responsive to an applied periodically-occurring sample clock from a sample clock circuit, are used to sample and then hold for a sample period the then-current phase of each of the MSB to Nth MSB output signals from comparators. Alternatively, a sample latch included in each of the group of comparators can replace the sample and hold circuits. Doubly-balanced mixers, each operating as either a modulator or a demodulator, are used to implement the biphase amplitude modulator, each of the comparators, each of the sample and hold circuits and sample clock circuit.
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