Patent ID: 7792215

Claim:
A direct-conversion receiver comprising: a Radio Frequency (RF) phase shifter for dividing an RF signal provided thereto into RF signals having phases of 0° and 90°; a Local Oscillation (LO) phase shifter for dividing an LO signal provided thereto into LO signals having phases of 0° and 90°; a single-phase channel frequency mixer for producing a baseband single-phase component by using the RF signal having 0° phase and the LO signals having 0° and 90° phases; and a quadrature phase channel frequency mixer for producing a quadrature phase component by using the RF signal having 90° phase and the LO signals having 0° and 90° phases, wherein the single-phase channel frequency mixer includes first and second pairs of transistors whose emitters and collectors are coupled with each other; and wherein the RF signal having 0° phase is applied to bases of first transistors in each of the first and second pairs and the LO signals having 0° and 90° phases are fed to bases of second transistors in each of the first and second pairs, respectively, to thereby cause a down-frequency conversion.