Wireless remote sensing thermometer

Abstract

A temperature measuring device comprises a ring oscillator having a nominal oscillating frequency positioned at a location where temperature is to be measured. The ring oscillator emits electromagnetic radiation to an antenna located at a convenient distance from the ring oscillator. The antenna transforms the electromagnetic radiation into an electrical signal. A receiver receives the electrical signal and measures the frequency of the electrical signal to determine the corresponding temperature. The temperature may then be visually monitored from a display or electronically monitored by other devices.

We claim: 
     
       1. A device for remotely measuring a temperature at a selected location, comprising: a ring oscillator having a nominal frequency that changes with changes in said temperature, wherein said oscillator is operably coupled to said location, and wherein said oscillator emits electromagnetic radiation at said frequency;   an antenna operably coupled for transforming said electromagnetic radiation to an electrical signal; and   a receiver operably coupled to said antenna for receiving said electrical signal to measure said frequency from said electrical signal for determining said temperature.   
     
     
       2. The device of claim 1, wherein said ring oscillator comprises a number of inverters serially connected in a closed loop. 
     
     
       3. The device of claim 1, wherein said nominal frequency is in the range of approximately 1 Hz to approximately 100 GHZ. 
     
     
       4. The device of claim 1, further comprising a display to display said temperature. 
     
     
       5. The device of claim 1, wherein said receiver outputs said temperature as an analog waveform. 
     
     
       6. The device of claim 1, wherein said receiver outputs said temperature as digital data. 
     
     
       7. The device of claim 1, further comprising a power source operably coupled to said oscillator.