Current driven polyphase filters and method of operation

DETAILED DESCRIPTION In accordance with the present invention, the disadvantages and problems associated with prior polyphase filters have been substantially reduced or eliminated.
In accordance with one embodiment of the present invention, a filter circuit includes a polyphase filter coupled to a first circuit component and a second circuit component.
The first circuit component propagates a first input current signal, a second input current signal, a third input current signal, and a fourth input current signal.
The third and fourth input current signals are substantially one-hundred-eighty degrees out of phase with the first and second input current signals.
The polyphase filter receives the first, second, third, and fourth input current signals.
The polyphase filter further generates a first output current signal; a second output current signal that is substantially ninety degrees out of phase with the first output current signal; a third output current signal that is substantially one-hundred-eighty degrees out of phase with the first output current signal; and a fourth output current signal that is substantially two-hundred-seventy degrees out of phase with the first output current signal.
The second circuit component generates a first output signal using the first output current signal and the third output current signal.
The first output signal is at a first phase.
The second circuit component further generates a second output signal using the second output current signal and the fourth output current signal.
The second output signal is at a second phase that is substantially ninety degrees out of phase with the first phase.
Another embodiment of the present invention is an image frequency rejection circuit that includes a first polyphase filter, a first mixer, a second mixer, and a second polyphase filter communicatively coupled to the first mixer and the second mixer.
The first polyphase filter generates a first LO signal and a second LO signal that is substantially ninety degrees out of phase with the first LO signal