| 摘要 |
A digital filter and method of filtering frequency translate or shift a spectrum of a digital input signal and further filter a translated signal to reduce or attenuate frequency components in the spectrum of the input signal. The digital filter includes first and second translators and a first filter. The first filter is connected between the first and second translators and is centered approximately at DC. The digital filter may further include a second filter, a third translator connected to an output of the second filter, a complex local oscillator connected to an LO input of each translator, and a complex-to-real converter connected to an output of the third translator. The method includes frequency translating the digital input signal and separately frequency translating a first translated signal after the first translated signal is filtered to produce a second translated signal.
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