Patent ID: 7984093

Claim:
A polyphase filter comprising: a first input configured to receive a first signal, the first signal having a first phase; a second input configured to receive a second signal, the second signal having a second phase; a third input configured to receive a third signal, the third signal having a third phase; a fourth input configured to receive a fourth signal, the fourth signal having a fourth phase; an impedance network; a first differential amplifier including a first non-inverting input and a first inverting input, wherein the first non-inverting input is in communication with the first input of the polyphase filter via the impedance network, and wherein the first inverting input is in communication with the second input of the polyphase filter via the impedance network, a first inverting output and a first non-inverting output; a second differential amplifier including a second non-inverting input and a second inverting input, wherein the second non-inverting input is in communication with the third input of the polyphase filter via the impedance network, and wherein the second inverting input is in communication with the fourth input of the polyphase filter via the impedance network, a second inverting output and a second non-inverting output; and a first resistance and a first capacitance with (i) a first end directly connected to the first non-inverting input and (ii) a second end directly connected to the fourth input of the polyphase filter.