Abstract: A radio transceiver is disclosed. The transceiver comprises an integrated circuit. The integrated circuit comprises a transmit path; a first switch coupled in series with the output of the transmit path; a receive path; and a second switch coupled as a shunt with the input of the receive path. The transceiver further comprises a plurality of external matching networks coupled to the transmit and receive paths of the integrated circuit to ensure minimal loading from one path to the other. The transceiver also comprises a shared balun for converting differential signals from the plurality of external matching networks to single ended signals; and an antenna to interface with the single ended signals. A method and system in accordance with an embodiment enables tying together the transmit path and the receive paths of a radio transceiver without the need for an external T/R switch.

Abstract: A circuit for single ended to differential conversion is disclosed. The circuit comprises a source for providing a single ended signal; and a transformer for receiving the single ended signal. The transformer includes first and second inductors. The first and second inductors are mutually coupled. When the operating frequency changes, a phase difference of currents flowing through the inductors changes, and therefore a phase difference between effective impedance of the first and second inductors changes to maintain a substantially 180 degree phase difference due to the mutual coupling.

Abstract: A circuit for single ended to differential conversion is disclosed. The circuit comprises a source for providing a single ended signal; and a transformer for receiving the single ended signal. The transformer includes first and second inductors. The first and second inductors are mutually coupled. When the operating frequency changes, a phase difference of currents flowing through the inductors changes, and therefore a phase difference between effective impedance of the first and second inductors changes to maintain a substantially 180 degree phase difference due to the mutual coupling.

Abstract: A radio transceiver is disclosed. The transceiver comprises an integrated circuit. The integrated circuit comprises a transmit path; a first switch coupled in series with the output of the transmit path; a receive path; and a second switch coupled as a shunt with the input of the receive path. The transceiver further comprises a plurality of external matching networks coupled to the transmit and receive paths of the integrated circuit to ensure minimal loading from one path to the other. The transceiver also comprises a shared balun for converting differential signals from the plurality of external matching networks to single ended signals; and an antenna to interface with the single ended signals. A method and system in accordance with an embodiment enables tying together the transmit path and the receive paths of a radio transceiver without the need for an external T/R switch.

Abstract: A system within a circuit is disclosed. The system comprises a first shield and a device above the first shield. The system also includes a plurality of conductive walls coupled to and extending from the first shield to block electromagnetic (EM) waves to other parts of the circuit. A system and method in accordance with the present invention adds metal walls on the edge of a sliced shield. The walls block the electromagnetic wave from coupling to other parts of the circuit from a sideways direction.

Abstract: A mixer is disclosed. In one embodiment, the mixer includes a polyphase filter that generates linear quadrature signals. The mixer also includes a potentiometric mixer that performs a frequency-conversion operation on the quadrature signal. According to the embodiments disclosed herein, the output of the potentiometric mixer has high linearity.

Abstract: A system within a circuit is disclosed. The system comprises a first shield and a device above the first shield. The system also includes a plurality of conductive walls coupled to and extending from the first shield to block electromagnetic (EM) waves to other parts of the circuit. A system and method in accordance with the present invention adds metal walls on the edge of a sliced shield. The walls block the electromagnetic wave from coupling to other parts of the circuit from a sideways direction. The use of this structure allows for more compact layout placement with insignificant degradation.