Abstract: A method and apparatus for an electronically tuned agile integrated bandpass filter is described. In one embodiment, the invention is an intermediate frequency filter for use in an integrated circuit. The filter includes a first filter stage, including a first LC resonator. The first filter stage further includes a first adjustable capacitor array coupled to the first LC resonator. The first adjustable capacitor array has an effective capacitance value adjustable through use of a first plurality of programmable data storage locations. The first plurality of programmable data storage locations are programmable through a serial control interface.

Abstract: A novel form of an integrated variable inductor uses an on-chip transformer together with a variable capacitor. The variable capacitor can either be a varactor or a switched capacitor array and is connected to the secondary coil of the transformer. By changing the capacitance at the secondary coil of a transformer, the equivalent inductance looking into the primary coil of the transformer can be adjusted. With another capacitor in parallel to the primary coil, two different modes of resonance inherently exist, and a very wide frequency tuning range can be achieved by combining the two modes.

Abstract: A novel form of an integrated variable inductor uses an on-chip transformer together with a variable capacitor. The variable capacitor can either be a varactor or a switched capacitor array and is connected to the secondary coil of the transformer. By changing the capacitance at the secondary coil of a transformer, the equivalent inductance looking into the primary coil of the transformer can be adjusted. With another capacitor in parallel to the primary coil, two different modes of resonance inherently exist, and a very wide frequency tuning range can be achieved by combining the two modes.

Abstract: There is a disclosed an oscillator for generating a periodic signal, comprising a transistor and two electro-magnetically coupled inductors in positive feedback configuration, one of the inductors is connected to the drain or gate of the transistor, and the other being connected to the source to maintain the same phase of the two voltages at the two nodes. Two or more of such single ended oscillators can be connected together to form a differential oscillator, and the invention can be generalized by the use of any active device and not just transistors.

Abstract: A method and apparatus for an electronically tuned agile integrated bandpass filter is described. In one embodiment, the invention is an intermediate frequency filter for use in an integrated circuit. The filter includes a first filter stage, including a first LC resonator. The first filter stage further includes a first adjustable capacitor array coupled to the first LC resonator. The first adjustable capacitor array has an effective capacitance value adjustable through use of a first plurality of programmable data storage locations. The first plurality of programmable data storage locations are programmable through a serial control interface.