Abstract: This invention provides a novel electronically tunable active duplexer for wireless transceiver applications. It relates to an active duplexer with full-duplex operation, permitting simultaneous transmission and reception of signals at same or different frequencies. It incorporates varactors, instead of fixed or mechanically adjustable capacitors, in phase shifting networks enabling one to electronically tune, with ease and precision, the frequency at which isolation is desired, over a band in both transmit and receive modes of operations. It can be implemented as a Monolithic Microwave Integrated Circuit (MMIC).

Abstract: A wireless sensor reader is provided to interface with a wireless sensor. The wireless sensor reader transmits an excitation pulse to cause the wireless sensor to generate a ring signal. The wireless sensor reader receives and amplifies the ring signal and sends the signal to a phase-locked loop. A voltage-controlled oscillator in the phase-locked loop locks onto the ring signal frequency and generates a count signal at a frequency related to the ring signal frequency. The voltage-controlled oscillator is placed into a hold mode where the control voltage is maintained constant to allow the count signal frequency to be determined.

Abstract: A machine includes a component. The machine may also include a position-sensing system with a plurality of sensor elements that each generate a signal related to proximity of the sensor element to the component by generating the signal based at least in part on the magnetic permeability of the space adjacent the sensor element and a time-varying magnetic field generated by an electric circuit of the position-sensing system. The machine may also include one or more information-processing devices that determine a positional relationship between the component and the plurality of sensor elements based on a plurality of the signals generated by the sensor elements.

Abstract: A speed sensing device for use with a traction device is disclosed. The speed sensing device has a rotor having a first rotational, wherein the rotor has magnets affixed thereon to generate a magnetic field. The speed sensing device also has a power-harvesting circuit coupled with the rotor to convert fluctuations in the magnetic field into electrical energy. The speed sensing device further has a sensor having a second rotational speed different from the first rotational speed, wherein the sensor is powered by the power-harvesting circuit to generate a signal indicative of a speed of the traction device. The speed sensing device still further has a transmitting circuit connected with the speed sensor and powered by the power-harvesting circuit to wirelessly transmit the generated signal.

Abstract: This invention provides a novel electronically tunable active duplexer for wireless transceiver applications. It relates to an active duplexer with full-duplex operation, permitting simultaneous transmission and reception of signals at same or different frequencies. It incorporates varactors, instead of fixed or mechanically adjustable capacitors, in phase shifting networks enabling one to electronically tune, with ease and precision, the frequency at which isolation is desired, over a band in both transmit and receive modes of operations. It can be implemented as a Monolithic Microwave Integrated Circuit (MMIC).