Patent ID: 8958769
Filing Date: 2015-02-17
Classification: H03D,H04B,H04L

Abstract:
1. A direct conversion receiver to demodulate a received frequency modulated transmission comprising: an input stage having an input and an output, said input being receptive to a frequency modulated transmission having a carrier frequency f a frequency modulated local oscillator providing a frequency modulated local oscillator signal, said frequency modulated local oscillator including a local oscillator having an output with a frequency approximately equal to f a mixer stage having inputs coupled to said output of said input stage and said output of said frequency modulated local oscillator to demodulate said frequency modulated transmission having said carrier frequency f an output stage; and a DC blocker stage coupled between said mixer stage and said output stage, said DC blacker stage having a cutoff frequency; wherein said modulation source provides the modulation signal having an amplitude δ corresponding to a desired degree of frequency deviation of the carrier frequency f wherein said frequency modulated local oscillator signal spreads low frequency components to a bandwidth higher than said cutoff frequency of said DC blocker stage during operation of said direct conversion receiver; wherein δ and f wherein effective average attenuation of said low frequency components is reduced and overall distortion performance of said direct conversion receiver is improved.