Embodiments of resonator circuits and modulating resonators and are described generally herein. One or more acoustic wave resonators may be coupled in series or parallel to generate tunable filters. One or more acoustic wave resonances may be modulated by one or more capacitors or tunable capacitors. One or more acoustic wave modules may also be switchable in a filter. Other embodiments may be described and claimed.

A radio frequency identification (RFID) tag includes an antenna, a power circuit, a tuning circuit, a receiver, and a backscatter transmitter. The power circuit is operably coupled to convert a radio frequency (RF) signal received via the antenna from an RFID reader into one or more power supply voltages. The tuning circuit is operably coupled to the antenna and to adjust an RF characteristic of the antenna and/or the tuning circuit based on a difference between a resonant frequency of the RFID tag and a carrier frequency of the RF signal. The receiver is operably coupled to receive a command signal from the RFID reader. The backscatter transmitter is operably coupled to transmit a response signal to the RFID reader via the antenna.

Devices and methods for improving voltage handling and/or bi-directionality of stacks of elements when connected between terminals are described. Such devices and method include use of symmetrical compensation capacitances, symmetrical series capacitors, or symmetrical sizing of the elements of the stack.

A digitally controlled oscillator (DCO) circuit is disclosed. The DCO circuit comprises a tuning circuit configured to tune an oscillation frequency of the DCO circuit based on processing an integer tuning codeword and a fractional tuning codeword associated with an input tuning codeword. In some embodiments, the tuning circuit comprises an integer tuning circuit configured to process the integer tuning codeword and a fractional tuning circuit configured to process the fractional tuning codeword, in order to implement the input tuning codeword. In some embodiments, the integer tuning codeword comprises an integer tuning range associated therewith and the fractional tuning codeword comprises a fractional tuning range associated therewith. In some embodiments, the fractional tuning range associated with the fractional tuning codeword is configured to cover more than one step of the integer tuning range associated with the integer tuning codeword.

A circuit and method are provided. The method couples a first bias signal to a first internal node and a second internal node via a first resistor and a second resistor, respectively, couples a second bias signal to a third internal node and a fourth internal node via a third resistor and a fourth resistor, respectively. The method further couples the first internal node to the second internal node via a switch of a first type controlled by a first control signal, couples the third internal node to the fourth internal node via a switch of a second type controlled by a second control signal, wherein the second control signal is an inversion of the first control signal, couples a first terminal to the first internal node and the third internal node via a first capacitor and a third capacitor, respectively; and couples a second terminal to the second internal node and the fourth internal node via a second capacitor and a fourth capacitor, respectively.

A wireless sensor includes a radio frequency (RF) receiving circuit operable to receive an RF signal having a carrier frequency of a plurality of carrier frequencies. The RF receiving circuit further includes a variable impedance where impedance of the variable impedance is a factor in establishing a resonant frequency of the RF receiving circuit. The wireless sensor further includes a processing module that is operable to determine a first value for a first impedance of the variable impedance for a known temperature based on the resonant frequency and the carrier frequency, determine a second value a second impedance of the variable impedance for an unknown temperature based on the resonant frequency and the carrier frequency, and determine a difference between the first and second values that corresponds to a change between the known temperature and the unknown temperature.

A circuit and method are provided. The method couples a first bias signal to a first internal node via a first resistor, couples a second bias signal to a second internal node via a second resistor, couples the first internal node to a ground node via a N-type switch, couples the second internal node to a power supply node via a P-type switch. The method further couples the first internal node to the second internal node via a transmission gate, couples a terminal to the first internal node via a first capacitor, and couples the terminal to the second internal node via a second capacitor.

A method includes a computing device transmitting a radio frequency (RF) signal to a passive wireless sensor. The RF signal includes a carrier frequency signal and a modulated sense request signal. The method further includes, in response to the modulated sense request signal, receiving, by the computing device, a response RF signal that includes the carrier frequency signal and a coded sense response signal from the passive wireless sensor. The coded sense response signal is representative of a sensed environmental condition by the passive wireless sensor. The method further includes generating, by the computing device, an environmental condition value based on the coded sense response signal and an environmental conversion information.

A circuit and method are provided. The method couples a first bias signal to a first internal node and a second internal node via a first resistor and a second resistor, respectively, couples a second bias signal to a third internal node and a fourth internal node via a third resistor and a fourth resistor, respectively. The method further couples the first internal node to the second internal node via a switch of a first type controlled by a first control signal, couples the third internal node to the fourth internal node via a switch of a second type controlled by a second control signal, wherein the second control signal is an inversion of the first control signal, couples a first terminal to the first internal node and the third internal node via a first capacitor and a third capacitor, respectively; and couples a second terminal to the second internal node and the fourth internal node via a second capacitor and a fourth capacitor, respectively.

A biasing circuit for biasing a switching transistor, wherein the switching transistor is used for switching a respective capacitor cell into/out of a capacitor array, wherein the capacitor array comprises one or more such capacitor cells, and wherein the capacitor array is coupled in parallel with a primary inductor to form an inductive/capacitive tank. The biasing circuit comprises a secondary inductor which is inductively coupled to the primary inductor, the secondary inductor configured to provide a bias signal for biasing the switching transistor.