Abstract: A semiconductor device includes a first Low Noise Amplifier (LNA), a second LNA, first and second receiving circuits, an a radio frequency multiplexer. The first LNA is connected to a first receiving port, and the second LNA is connected to a second receiving port different from the first receiving port. The first receiving circuit includes a first transformer and processes one or more outputs of the first and second LNAs. The second receiving circuit processes one or more of the outputs of the first and second LNAs. The radio frequency multiplexer controls connection between the first and second LNAs and the first and second receiving circuits. The first receiving circuit includes a first variable capacitor having a first end connected to an output of the radio frequency multiplexer and a second end connected to the first transformer.

Abstract: 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.

Abstract: 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.

Abstract: A transceiver and a method operating the transceiver are provided. The transceiver includes a first communication module configured to receive a first signal based on a first communication scheme; a second communication module configured to receive a second signal based on a second communication scheme; a reception module having a low-power circuit configured to detect a signal in a frequency band which can be used by the first communication module and the second communication module; and a controller configured to establish channels for the first communication module or the second communication module based on a strength of the signal detected by the reception module.

Abstract: A transceiver and a method operating the transceiver are provided. The transceiver includes a first communication module configured to receive a first signal based on a first communication scheme; a second communication module configured to receive a second signal based on a second communication scheme; a reception module having a low-power circuit configured to detect a signal in a frequency band which can be used by the first communication module and the second communication module; and a controller configured to establish channels for the first communication module or the second communication module based on a strength of the signal detected by the reception module.

Abstract: A DAC circuit using a charge subtraction method and a change transfer interpolation method includes resistor cells configured to divide a voltage of data of total K bits (=upper M bits+lower N bits) by resistance dividers; a decoder group configured to receive digital data of the M bits and the N bits divided in the resistor cells, process the digital data by the unit of 2 bits, and output respective corresponding voltages; a capacitor group configured to receive the voltages outputted from the decoder group and realize charge charging by a charge subtraction method and charge transferring by a charge transfer interpolation method; and an operational amplifier having a first input terminal which receives a reference voltage and a second input terminal which receives an interpolation voltage corresponding to an amount of charges transferred from the capacitor group, and configured to generate an output voltage.