Techniques for co-tuning of inductance (L) and capacitance (C) in a VNCAP-based LC tank oscillator are provided. In one aspect, an LC tank oscillator includes: a capacitor including at least two metal layers, each metal layer having metal fingers that are interdigitated, wherein an orientation of the metal fingers alternates amongst the at least two metal layers; and an inductor on the capacitor. Inter-layer vias can be present interconnecting the at least two metal layers creating conductive loops between the metal fingers, wherein an arrangement of the inter-layer vias in an area between the at least two metal layers is configured to co-tune both inductance and capacitance in the LC tank oscillator. A method of operating an LC tank oscillator and a method of co-tuning inductance and capacitance in an LC tank oscillator are also provided.

A fast response time, self-activating, adjustable threshold limiter including a limiting element LE, a first coupling element CE.sub.1 electrically connected from a signal node of LE to a control input of LE, and a second coupling element CE.sub.2 electrically connected from the control input of LE to a nominal node of LE. An initial bias (control) voltage is also supplied to the control input of LE to dynamically control the limiting threshold for the limiter. Embodiments include usage of self-activating adjustable power limiters in combination with series switch components in a switch circuit in lieu of conventional shunt switches.

A clock generating circuit is operated in a phase-locking mode to generate an output clock signal having a first frequency that is phased-locked with respect to a variable-frequency input clock signal. After a frequency transition in the input clock signal, phase-locking is disabled within the clock generating circuit to transition the output clock signal from the first frequency to a second frequency that lacks phase-alignment with the input clock signal, then a frequency-lock range of the clock generating circuit is adjusted to transition the output clock signal from the second frequency to a third frequency that also lacks phase alignment with the input clock signal. After adjusting the frequency-lock range of the clock generating circuit, phase-locking is re-enabled therein to transition the output clock signal from the third frequency to a fourth frequency that is phase-aligned with the variable-frequency input clock signal.

A circuit includes a first digital controlled oscillator and a second digital controlled oscillator coupled to the first digital controlled oscillator. A skew detector is connected to determine a skew between outputs of the first digital controlled oscillator and the second digital controlled oscillator, and a decoder is utilized to output a control signal, based on the skew, to modify a frequency of the first digital controlled oscillator using a switched capacitor array to reduce or eliminate the skew.

In a first clock frequency multiplier, multiple injection-locked oscillators (ILOs) having spectrally-staggered lock ranges are operated in parallel to effect a collective input frequency range substantially wider than that of a solitary ILO. After each input frequency change, the ILO output clocks may be evaluated according to one or more qualifying criteria to select one of the ILOs as the final clock source. In a second clock frequency multiplier, a flexible-injection-rate injection-locked oscillator locks to super-harmonic, sub-harmonic or at-frequency injection pulses, seamlessly transitioning between the different injection pulse rates to enable a broad input frequency range. The frequency multiplication factor effected by the first and/or second clock frequency multipliers in response to an input clock is determined on the fly and then compared with a programmed (desired) multiplication factor to select between different frequency-divided instances of the frequency-multiplied clock.

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 system is described for maintaining an inductive-capacitive (LC) network at resonance while the excitation frequency may be varied between a number of discrete frequencies at desired instants controlled by a modulation input, while taking into account component parameter errors due environmental and ageing as well as manufacturing tolerances. Control of the resonance while the excitation frequency changes permits the transmission of frequency modulation (FM) or frequency shift keying (FSK) information through an inductively coupled power transfer system.

A method for execution by a RFID tag includes receiving, by an antenna of the RFID tag, an RF signal from an RFID reader, where the RF signal has a carrier frequency. The method further includes determining, by a tuning circuit of the RFID tag, a received power level of the RF signal at the carrier frequency and whether the received power level compares favorably to a power level threshold. When the received power level compares unfavorably to the power level threshold, the method further includes adjusting, by the tuning circuit, the input impedance of the RFID tag by adjusting a tank circuit of the RFID tag until the received power level compares favorably to the power level threshold, where the input impedance of the RFID tag is based on one or more of impedance of the antenna and impedance of the tank circuit.

A method includes sending, by a reader, a radio frequency (RF) signal to a wireless sensor that includes an antenna having a tail section and a head section. The tail section is for placement in an RF limited area for sensing moisture in a first location of a vehicle under test and wherein the head section is for placement in a non-RF limited area. The method further includes receiving, by the reader, an RF response to the RF signal from the wireless sensor. The first RF response includes an indication of adjustment of one or more RF characteristics of the wireless sensor, which corresponds to a variance of the one or more RF characteristics from a desired value, which, in turn, corresponds to a level of moisture at the first location. The method further includes outputting, by the reader, a message regarding the level of moisture at the first location.

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.