Sensor assembly capable of obtaining and providing a measurement of a
physical quantity, e.g., measurement of temperature and/or pressure of a
vehicular tire, includes an antenna capable of receiving a radio
frequency signal, a radio frequency identification (RFID) device coupled
to the antenna, a sensor coupled to the RFID device arranged to generate
a measurement of the physical quantity or quantities, and a switch
coupled to the RFID device and arranged to connect or disconnect the
sensor from a circuit with the antenna dependent on whether the antenna
receives a particular signal associated with the RFID device. When the
antenna receives the particular signal associated with the RFID device,
the RFID device causes the switch to close and connect the sensor in the
circuit with the antenna to enable the measurement generated by the
sensor to be directed to and transmitted by the antenna.