Patent ID: 7076011

Claim:
An apparatus for down-converting and filtering an input signal, comprising: a frequency down-converter that includes a switch and a capacitor, wherein the switch undersamples the input signal according to a periodic control signal to produce a down-converted signal, wherein a period of said control signal is defined by a first phase and a second phase, wherein said first phase and said second phase each include a respective pulse having a pulse width, wherein said pulse during said first phase of said control signal causes said switch to close and sub-sample the input signal over said pulse of said first phase, wherein energy is transferred from the input signal and stored in said capacitor during said pulse of said first phase, and wherein an instance of the down-converted signal is generated from the transferred energy; a first delay module that delays said down-converted signal; a first scaling module that scales an output of said first delay module; a second delay module that delays said output of said first delay module; a second scaling module that scales an output of said second delay module; and an adder that sums at least said output of said first scaling module and said output of said second scaling module, to generate a filtered and down-converted output signal.