Abstract: Systems and methods are described that provide global positioning system (GPS) enabled wireless communications. The wireless communications system provides a switching module that is adapted to couple communications circuitry to a first antenna or a second antenna as a function of communications characteristics of the first antenna or the second antenna. The switching module is also adapted to couple GPS circuitry to a first antenna or a second antenna as a function of GPS reception characteristics of the first antenna or the second antenna. The switching module may also provide the communications circuitry and the GPS circuitry with simultaneous access to different antennas.

Abstract: A system and a method for providing a global positioning system (GPS) enabled antenna system are provided. The GPS enabled antenna may be used, for example, on a wireless communications device such as a wireless handset. The wireless communications device may include a switching module that can selectively switch communications signals between the antenna and one of a plurality of communications band circuits. A respective impedance matching circuit may be provided between the switching module and particular communications band circuitry to match or to tune the antenna to the particular communications band circuitry.

Abstract: A receiver uses an adaptive algorithm to tune a low-cost crystal oscillator according to a temperature compensation profile so as to produce a precision master reference frequency despite temperature, initial tolerance, and aging effects. An automatic frequency control system also tunes the crystal oscillator. The adaptive algorithm adjusts the temperature compensation profile for the crystal oscillator according to the adjustments made by the automatic frequency control should a received signal's quality factor exceed that associated with the temperature compensation profile.

Abstract: A crystal oscillator having tunable ferroelectric components. A first ferroelectric capacitor is coupled to an automatic frequency control line for fine tuning the reference frequency. A second ferroelectric capacitor is coupled to temperature compensation control circuitry that applies a correction voltage to the second capacitor to vary the reference frequency in response to ambient temperature changes. A third ferroelectric capacitor has a capacitance that is adjusted and fixed during manufacture to set the initial tolerance of the crystal oscillator at ambient temperature.

Abstract: A tunable low noise amplifier matching circuit is provided. The matching circuit includes a ferroelectric tunable component. A control signal is applied to the tunable component, changing the component's impedance. This changes the impedance or the noise figure response, or both, of the matching circuit.

Abstract: A power amplifier matching circuit is provided. The matching circuit includes a ferro-electric tunable component. A control signal is applied to the tunable component, changing the component's impedance. This changes the impedance of the matching circuit.

Abstract: A voltage controlled oscillator incorporating a ferroelectric capacitor in its resonant circuit is provided in order to provide superior phase noise performance and a linear control voltage/capacitance relationship. The resonant circuit may include multiple ferroelectric capacitors and multiple control voltages in order to provide band switching capability and/or increase the tuning range of the oscillator. The feedback loop of the oscillator may also incorporate a ferroelectric capacitor in order to adaptively optimize the feedback.