| 摘要 |
In accordance with one form of the present invention, an Adaptively Peaked Super-Regenerative Filter (APSRF) is provided, which preferably includes an interference suppression system (ISS), a summing block, a phase splitter, one or more variable attenuators, three couplers, an amplifier and a filter. The APSRF provides for significant narrowing of the bandwidth and a significant increase in the SNR and Q transfer function of the filter. The output of the amplifier or filter is sampled by one of the couplers and used as a reference sample signal to the ISS. The ISS includes an adaptive loop, which adjusts the reference sample signal in phase and amplitude to form a replica signal. The replica signal is designed to cancel an input sample signal taken from another coupler and applied to the summing block. An output of the summing block provides an error sample signal to the ISS, which enables the ISS to adaptively optimize the nulling function by adjusting the amplitude and phase of the replica signal. The phase splitter provides a copy of the replica signal having a 180-degree phase shift. This copy is in phase with the input signal, and provides a positive or regenerative feedback signal, which is coupled to the input signal. The copy of the replica signal is passed through a variable attenuator, and by varying the magnitude of the regenerative feedback, the degree of bandwidth reduction can be adjusted over a broad range.
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