Patent ID: 7184740

Claim:
A direct conversion receiver comprising: a poly-phase filter that generates an in-phase differential signal and a quadrature-phase differential signal derived from a received radio frequency (RF) signal; an in-phase mixer which mixes the in-phase differential signal with a first local oscillation signal and a second local oscillation signal; a quadrature-phase mixer which mixes the quadrature-phase differential signal with the first local oscillation signal and a third local oscillation signal; and a mismatch estimation unit configured to estimate the phase mismatch caused by the poly-phase filter and/or by the in-phase mixer and the quadrature-phase mixer, from output signals of the in-phase mixer and the of quadrature-phase mixer; and at least one variable phase shifter for adjusting the phase mismatch in response to an output signal of the mismatch estimation unit.