Abstract: Apparatus and methods for providing integrated RF notch filter subsystems having enhanced Q values are described. An integrated notch filter includes an LC filter element and a Q-enhancement circuit coupled to the LC filter element, with the Q-enhancement circuit configured to offset resistive losses in the LC filter element to adjust the Q value of the filter system. A transceiver having multiple LNAs for various bands may be provided to a single notch filter system including a Q-enhancement circuit.

Abstract: Systems for multi-mode phase modulation are disclosed. Systems provide for direct modulation of a multi-mode voltage controlled oscillator (VCO). A fractional-N counter may be used in a phase-locked loop (PLL) to synthesize a radio frequency carrier signal. The multi-mode VCO may be characterized by a first frequency gain during operation in a first mode and by a second frequency gain during operation in a second mode where signals controlling the first and second operating modes are provided by a control circuit. The control circuit may include a switch to provide control signals to the VCO.

Abstract: Systems and methods are provided for capture control of video data from a capsule camera system having an on-board storage or wireless transmission. The capsule camera system moves through the GI tract under the action of peristalsis and records images of the intestinal walls. For some periods of time, the capsule camera system may move very slowly and there are little differences in the image data between different frames. These frames can be designated for discard to conserve storage space or conserve power. A capsule control processing unit is incorporated to evaluate motion metric based on image data associated with a current frame and a previous frame. A decision is made based on a profile of the motion metric to select an operation mode from a group comprising Capture Mode and Conservation Mode. The capsule camera system is then operated according to the selected operation mode.

Abstract: System for dual diversity receiver using switched LNAs. A dual diversity receiver is provided that includes two antennas to receive a radio signal, where each antenna produces an antenna signal that is representative of the received radio signal. The receiver includes first and second LNAs that receive the respective antenna signals and output first and second amplified signals. The receiver also includes logic to determine the stronger antenna signal and select one of the LNA outputs for processing by the receiver.

Abstract: Systems and methods are provided for capture control of video data from a capsule camera system having an on-board storage or wireless transmission. The capsule camera system moves through the GI tract under the action of peristalsis and records images of the intestinal walls. For some periods of time, the capsule camera system may move very slowly and there are little differences in the image data between different frames. These frames can be designated for discard to conserve storage space or conserve power. A capsule control processing unit is incorporated to evaluate motion metric based on image data associated with a current frame and a previous frame. A decision is made based on a profile of the motion metric to select an operation mode from a group comprising Capture Mode and Conservation Mode. The capsule camera system is then operated according to the selected operation mode.

Abstract: Methods and apparatus for calibrating the VCO element of a phase-locked loop to correct for non-linearities are disclosed. The modulation port of the VCO may be characterized to generate a tuning model, which may then be used to generate a correction signal to be combined with an input signal and applied to the VCO modulation port. The tuning model may be based on a third or higher order polynomial generated from a plurality of open-loop frequency measurements of the VCO.

Abstract: A system and method for providing, among other things, wideband phase modulation is described. Several embodiments include a scaling network for scaling an input modulation signal in accordance with a scaling parameter and thereby generating a scaled modulation signal that is applied to a voltage-controlled oscillator of a phase-locked loop. A sensing network may also be included for detecting changes in one or more parameters characterizing the voltage-controlled oscillator. A calibration adjustment network may additionally be included for adjusting the scaling parameter in accordance with the changes in the one or more parameters.

Abstract: An alignment apparatus for use with a polar transmitter system is disclosed herein. The alignment apparatus includes a signal alignment module configured to apply an amplitude modulation control signal and a frequency modulation control signal to the polar transmitter in accordance with a defined timing relationship. A time alignment network, operatively coupled between an output of the polar transmitter system and the signal alignment module, sets the defined timing relationship.

Abstract: Variable gain commutating amplifier apparatus and methods for use in a polar modulator are described. The apparatus may include two or more commutating amplifier stages configured to be switched to an output load based on a desired amplitude and/or transmit power level. The amplifier stages may include cross-coupled differential pairs to cancel RF carrier feedthrough. An additional R-2R ladder circuit may be provided to further extend the dynamic range by reducing the output power at the lowest output stages.

Abstract: Apparatus and methods for improving the performance of a modulator, typically in an I/Q modulation system, are described. Input I and Q current modulation signals may be processed to generate a sign signal and a magnitude signal, with the magnitude signal selectively applied to the inputs of a mixer based on the sign signal so as to generate respective I and Q modulation signal components. These may then be combined to generate a composite modulation signal.

Abstract: Systems and methods for nulling offsets in differential signaling systems are described. A first circuit may be configured to sense the difference between a first differential current and a second differential current and provide a sense signal to an adjustment circuit. The adjustment circuit may be configured to generate a correction signal based on the sense signal, where the correction signal is combined with the first differential current to reduce the offset between the first differential current and the second differential current. Alternately, the correction signal may be combined with the first and second differential currents to reduce the offset. The process may be repeated until the corrected first differential current and the second differential current are within a desired tolerance.

Abstract: Systems and methods are provided for motion detection and capture control of video data from a capsule camera system having an on-board storage. The capsule camera system moves through the GI tract under the action of peristalsis and records images of the intestinal walls. The capsule's movement is episodic and jerky. The capacity of the on-board storage is limited. In order to avoid unnecessary capture of images when the capsule camera moves very slowly or stalls, motion detection technique is utilized to help control image capture. Furthermore, an adaptive capture control is disclosed that automatically adjusts the threshold level of capture control to maintain proper image capture. The invented capture control also conserves precious battery power by eliminating capture of unnecessary images when the capsule camera moves too slowly or stalls.

Abstract: An apparatus for providing a two point phase/frequency modulation system is disclosed herein. The apparatus includes a first network configured to introduce an offset to center a signal applied to a VCO. The apparatus further includes a second network configured to set a gain of the VCO. A phase tracking network is configured to dynamically adjust the offset and the gain.

Abstract: Linear wideband phase modulation system. Apparatus is provided for linear phase modulation utilizing a phase-locked loop. The apparatus includes a limiting circuit that restricts a range of a modulation signal that is coupled to a voltage controlled oscillator (VCO) associated with the phase-locked loop, and a linearizing circuit that reshapes the modulation signal to improve linearity.

Abstract: System for linear amplitude modulation. Apparatus is provided for linear amplitude modulation of an amplifier. The apparatus includes a processing circuit that receives an amplitude modulation signal and produces one or more amplifier control signals that are coupled to the amplifier. The apparatus also includes a feedback circuit that generates a feedback signal from an output of the amplifier that is input to the processing circuit; and a network that controls a bias of the amplifier in response to the feedback signal to linearize the amplifier's amplitude control.