A method and circuit for controlling a multi-use horn by a bus are disclosed. The circuit comprises a bus signal receiving and transmitting unit used for receiving and transmitting a horn control instruction from a vehicle-mounted computer controller by the bus, a control unit used for generating a horn sounding signal adapting to a current scene according to the horn control instruction, and a horn sounding unit used for making sounds according to the horn sounding signal. By adoption of the method and circuit, the horn is connected to the vehicle-mounted computer controller by the bus and is controlled by the vehicle-mounted computer controller to make sounds, and thus, sound requirements for various horns for different uses on vehicles and engineering machines are met.

A method and circuit for controlling a multi-use horn by a bus are disclosed. The circuit comprises a bus signal receiving and transmitting unit used for receiving and transmitting a horn control instruction from a vehicle-mounted computer controller by the bus, a control unit used for generating a horn sounding signal adapting to a current scene according to the horn control instruction, and a horn sounding unit used for making sounds according to the horn sounding signal. By adoption of the method and circuit, the horn is connected to the vehicle-mounted computer controller by the bus and is controlled by the vehicle-mounted computer controller to make sounds, and thus, sound requirements for various horns for different uses on vehicles and engineering machines are met.

Methods and devices providing Positive Logic biasing schemes for use in a digitally tuning capacitor in an integrated circuit device are described. The described methods can be used in integrated circuits with stringent requirements in terms of switching time, power handling, noise sensitivity and power consumption. The described devices include DC blocking capacitors arranged in series with stacked switches coupled to RF nodes. The stacked FET switches receive non-negative supply voltages through their drains and gates during the ON and OFF states to adjust the capacitance between the two nodes.

Methods and devices providing Positive Logic biasing schemes for use in a digitally tuning capacitor in an integrated circuit device are described. The described methods can be used in integrated circuits with stringent requirements in terms of switching time, power handling, noise sensitivity and power consumption. The described devices include DC blocking capacitors arranged in series with stacked switches coupled to RF nodes. The stacked FET switches receive non-negative supply voltages through their drains and gates during the ON and OFF states to adjust the capacitance between the two nodes.

A variable filter and method of switching a resonant frequency of the variable filter from an initial frequency to a desired frequency, where the variable filter has a tunable frequency and a variable Q. With the variable filter operating at the initial frequency and an initial Q, the variable filter is Q-spoiled toward a low-Q state. The variable filter is tuned toward the desired frequency and the tunable resonator is Q-enhanced from the low-Q state to achieve a desired filter response.

A wireless communication system includes a plurality of wireless sensors. A wireless sensor includes a radio frequency (RF) receiving circuit, and a sensing element, where the sensing element affects the resonant frequency of the RF receiving circuit. The wireless sensor further includes a processing module operable to determine a first value for an adjustable element of a plurality of elements for a known environmental condition, a second value for the adjustable element for an unknown environmental condition, a difference between the first and second values that corresponds to a change, and to generate a coded value representative of the change. The wireless communication system further includes one or more sensor computing devices coupled to the plurality of wireless sensors via a network. A sensor computing device includes a second processing module operable to receive the coded value and determine a sensed environmental condition based on the coded value.

A wireless communication system includes a plurality of wireless sensors. A wireless sensor includes a radio frequency (RF) receiving circuit, and a sensing element, where the sensing element affects the resonant frequency of the RF receiving circuit. The wireless sensor further includes a processing module operable to determine a first value for an adjustable element of a plurality of elements for a known environmental condition, a second value for the adjustable element for an unknown environmental condition, a difference between the first and second values that corresponds to a change, and to generate a coded value representative of the change. The wireless communication system further includes one or more sensor computing devices coupled to the plurality of wireless sensors via a network. A sensor computing device includes a second processing module operable to receive the coded value and determine a sensed environmental condition based on the coded value.

A passive wireless temperature sensor includes a radio frequency (RF) front end having a variable input impedance. The RF front end includes an antenna operable to receive an RF signal having a particular carrier frequency and a tuning circuit having a resonant frequency corresponding to the particular carrier frequency. The passive wireless temperature sensor further includes one or more temperature sensing elements coupled to the RF front end. When sensing a temperature, the one or more temperature sensing elements cause a change in the variable input impedance. The passive wireless temperature sensor further includes a processing module operably coupled to the RF front end operable to adjust the resonant frequency of the tuning circuit to compensate for the change in the variable input impedance and generate a coded value representative of the change. The coded value representative of the change corresponds to the sensed temperature.

A passive wireless temperature sensor includes a radio frequency (RF) front end having a variable input impedance. The RF front end includes an antenna operable to receive an RF signal having a particular carrier frequency and a tuning circuit having a resonant frequency corresponding to the particular carrier frequency. The passive wireless temperature sensor further includes one or more temperature sensing elements coupled to the RF front end. When sensing a temperature, the one or more temperature sensing elements cause a change in the variable input impedance. The passive wireless temperature sensor further includes a processing module operably coupled to the RF front end operable to adjust the resonant frequency of the tuning circuit to compensate for the change in the variable input impedance and generate a coded value representative of the change. The coded value representative of the change corresponds to the sensed temperature.

A passive tunable integrated circuit (PTIC) having an electro-static discharge (ESD) protection circuit is disclosed. The ESD protection circuit includes at least one spark gap that has a breakdown voltage determined by design parameters. The at least one spark gaps are configured to route signals above a breakdown voltage to ground in order to protect a variable capacitor. The design parameters can be based on a material (Barium Strontium Titanate), a structure, and a fabrication process of the PTIC and further based on expected ESD signals for a mobile device application.