MEMS SAW sensor

A SAW sensor for sensing temperature and pressure within an environment, comprising:

• a piezoelectric substrate having a top surface;
• an interdigital transducer coupled to the top surface of the substrate, said interdigital transducer adapted to transmit and receive surface acoustic waves along a SAW delay line of the sensor;
• one or more temperature sensing reflectors adapted to reflect surface acoustic waves transmitted along a first direction of the SAW delay line;
• a diaphragm having a compressive zone and a stretched zone;
• and
• one or more pressure sensing reflectors disposed on the compressive zone of the diaphragm and adapted to reflect surface acoustic waves transmitted along a second direction of the SAW delay line.

A SAW sensor for sensing temperature and pressure within an environment, comprising:

• an electrode structure adapted to transmit and receive surface acoustic waves along a SAW delay line of the sensor;
• a single temperature sensing reflector adapted to reflect surface acoustic waves transmitted along a first direction of the SAW delay line;
• a diaphragm having a compressive zone and a stretched zone;
• a single pressure sensing reflector disposed on the compressive zone of the diaphragm and adapted to reflect surface acoustic waves transmitted along a second direction of the SAW delay line;
• and
• a single reference reflector adapted to provide a referenced phase response for both temperature and pressure measurement of the SAW sensor.

A SAW sensor for sensing temperature and pressure within an environment, comprising:

• an interdigital transducer adapted to transmit and receive surface acoustic waves along a SAW delay line of the sensor;
• temperature sensing means for sensing temperature within the environment, said temperature sensing means adapted to reflect surface acoustic waves transmitted along a first direction of the SAW delay line;
• pressure sensing means for sensing pressure within the environment, said pressure sensing means adapted to reflect surface acoustic waves transmitted along a second direction of the SAW delay line;
• means for wirelessly receiving a power signal to power the SAW sensor;
• and
• means for wirelessly transmitting an RF response signal from the SAW sensor.

A sensor system for acoustically sensing temperature and pressure within an environment, comprising:

• A SAW sensor including an electrode structure adapted to transmit and receive surface acoustic waves along a SAW delay line, said SAW sensor including temperature sensing means for measuring temperature along a first direction of the SAW delay line and pressure sensing means for measuring pressure along a second direction of the SAW delay line;
• means for wirelessly providing power to the SAW sensor;
• and
• means for wirelessly transmitting an RF response signal from the SAW sensor.

A method of wirelessly and passively measuring temperature and pressure within an environment, comprising the steps of:

• providing a SAW sensor including an electrode structure adapted to transmit and receive surface acoustic waves along a SAW delay line having a +x direction and a −x direction;
• wirelessly powering the electrode structure and transmitting incident surface acoustic waves in both the +x direction and −x direction of the SAW delay line;
• providing one or more temperature sensing reflectors in acoustic communication with the +x direction of the SAW delay line, said one or more temperature reflectors adapted to reflect echo signals back to the electrode structure;
• providing a diaphragm and one or more pressure sensing reflectors in acoustic communication with the −x direction of the SAW delay line, said one or more pressure sensing reflectors adapted to reflect echo signals back to the electrode structure;
• outputting a wireless RF response signal;
• and
• analyzing the RF response signal to obtain a measure of the temperature and pressure within the environment.