A receiver circuit is provided. The receiver circuit includes an antenna configured to receive a radio frequency (RF) signal; a filter configured to filter the RF signal received by the antenna; and a passive mixer circuit configured to adjust a center frequency of the filtered RF signal to a predetermined frequency. The passive mixer circuit includes: a transformer which includes a first coil and a second coil that is separate from the first coil; a first passive mixer which is directly connected to a first end of the second coil; and a second passive mixer which is directly connected to a second end of the second coil and is separate from the first passive mixer.