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 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.sub.; 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 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.

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 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 power detector for use in an RF receiver. The detector includes a power reference generator and a power quantizer. The power reference generator develops a power reference current, voltage, or signal as a function of a power transferred via a received RF signal. The power quantizer is responsive to the power reference current, voltage, or signal to develop a digital field power value indicative of the power reference current, voltage, or signal.

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 radio frequency identification (RFID) tag includes an antenna structure, a tank circuit, and a processing module that includes a tuning circuit. The processing module requires a processing module power level to operate according to a protocol. The tuning circuit requires a tuning circuit power level to adjust input impedance. The processing module power level is greater than the tuning circuit level. The processing module measures a first power level from a received RF signal. When the first power level is greater than the tuning circuit power level but less than the processing module power level, the processing module adjusts the input impedance to increase efficiency of power measurement and measures a second power level from the received RF signal. When and the second power level is greater than the processing module power level, the processing module uses the second power level to operate according to the protocol.

A circuit for calibrating an injection locked oscillator is provided. The injection locked oscillator includes an injection locking input, an LC tank and an oscillator output to output an oscillator output signal. The circuit is configured to adjust a capacitance of the LC tank to different values, detect an amplitude of the oscillator output signal for each value of the different values of the capacitance while an input signal having a target frequency is applied to the injection locking input, determine a maximum amplitude of the detected amplitudes, and select a value for operating the injection locked oscillator based on the determined maximum amplitude.

An apparatus is disclosed including a wireless transceiver implementing transformer reconfigurability. In an example aspect, the apparatus includes a common single-ended node, a common differential node pair, and a transceiver path set. The transceiver path set includes a first transceiver path and a second transceiver path. The first transceiver path comprises a first single-ended interface and a first differential interface and includes a first transformer. The second transceiver path comprises a second single-ended interface and a second differential interface and includes a second transformer. The apparatus also includes single-ended switch circuitry and differential switch circuitry. The single-ended switch circuitry is coupled between each transceiver path of the transceiver path set and the common single-ended node. The differential switch circuitry is coupled between each transceiver path of the transceiver path set and the common differential node pair. Alternatively, an apparatus can include multiple single-ended nodes including first and second single-ended nodes.