Abstract: A surface acoustic wave sensor system for determining environmental conditions on a substrate. The system comprises an interrogator for producing an RF interrogating signal transmitted by an antenna to an interdigital transducer mounted on the substrate for producing an incident surface acoustic wave responsive to the interrogating signal. A plurality of reflector arrays mounted on the substrate produce a like plurality of reflected surface acoustic waves; a spacing between adjacent ones of the plurality of reflector arrays comprising a non-uniform distance. The plurality of reflected surface acoustic waves are responsive to the environmental condition and exhibit a characteristic from which the environmental condition can be determined by a processing component.

Abstract: A method is provided for determining a number of revolutions per minute (RPM) of a rotating object. The method includes transmitting interrogation signals at a regular period from a fixed antenna positioned adjacent to the rotating object. The method also includes transmitting echo signals from a sensor antenna positioned on the rotating object, in response to the interrogation signals. The method also includes counting a number of echo signals detected by the fixed antenna, during one revolution of the object. The method also includes determining the RPM of the rotating object based on the number of response signals and the regular period of the signals. A system is also provided for determining the number of revolutions per minute (RPM) of the rotating object.

Abstract: A sensor system for determining deformation of an object subject to forces. The sensor system comprises an object upon which forces are exerted and a cavity within the object, a first substrate for supporting surface acoustic waves in an upper surface of the first substrate, the first substrate disposed in the cavity, a first surface acoustic wave transducer disposed on the upper surface and responsive to an interrogation signal for generating an incident surface acoustic wave in the upper surface, a first reflector array responsive to the incident surface acoustic wave for creating reflected surface acoustic waves on the upper surface, the reflected surface acoustic waves received by the transducer and having characteristics indicative of strain deformation of the object due to a force exerted on the object.

Abstract: A strain sensor for determining a strain experienced by a body under test in response to forces exerted on the body-under-test. The strain sensor comprises an interface member mounted on a surface of the body-under-test and a SAW sensor mounted on a surface of the interface member. The strain in the body-under-test is translated to strain in the SAW sensor and determined by the SAW sensor. The strain in the SAW sensor is responsive to the strain in the body-under-test.

Abstract: A surface acoustic wave sensor system for use with a moving platform. The system comprises an interrogator for producing an RF interrogating signal transmitted from a first antenna. A substrate that supports surface acoustic waves is attached to the moving platform and an interdigital transducer (IDT) and reflector are mounted on the substrate. The IDT produces surface acoustic waves (SAW) responsive to the RF interrogating signal. The reflector produces reflected SAW responsive to the incident SAW and responsive to a characteristic of the moving platform. A position indicator produces a synchronization signal input to the interrogator for triggering the RF interrogating signal. The synchronization signal is timed to trigger the RF interrogating signal when the interdigital transducer is within a field-of-view of the first antenna.

Abstract: A surface acoustic wave (SAW) device package and method for packaging a SAW device provide a surface excited device having a small footprint, low cost and fabricated according to a unique manufacturing process. A substrate including a SAW active area on a first side is bonded to another similar sized substrate with a space sufficient to allow the propagation of the SAW on a top surface of the substrate. The two substrates have similar thermal expansion coefficients such that stress from the sealing process is minimized. The two substrates are sealed using either a low melting point glass or an organic compound such that conductive pathways exist through the seal allowing the internal device to access an external electrical connection.

Abstract: A SAW sensor disposed in on a material. The sensor comprises an antenna having a sacrificial link in at least one antenna element, wherein the sacrificial link is exposed to degrading elements within or on a surface of the material, a SAW transducer responsive to an interrogation signal for generating an incident acoustic wave, a reflector responsive to the incident SAW for creating a reflected SAW, the reflected SAW received by the transducer, the transducer for creating a response signal responsive to the reflected SAW, and the response signal transmitted from the antenna, characteristics of the response signal dependent on a condition of the sacrificial link.

Abstract: A strain sensor for determining a strain experienced by a body under test in response to forces exerted on the body-under-test. The strain sensor comprises an interface member mounted on a surface of the body-under-test and a SAW sensor mounted on a surface of the interface member. The strain in the body-under-test is translated to strain in the SAW sensor and determined by the SAW sensor. The strain in the SAW sensor is responsive to the strain in the body-under-test.

Abstract: A surface acoustic wave device responsive to an interrogation signal for producing a return signal. The surface acoustic wave device comprises an antenna for receiving the interrogation signal, a piezoelectric substrate, one or more frequency-selective reflective arrays disposed on the piezoelectric substrate, an interdigital transducer for launching an incident surface acoustic wave on the substrate in response to the interrogation signal, the incident surface acoustic wave propagating to the one or more frequency-selective reflective arrays, a reflected surface acoustic wave reflected from each one of the reflective arrays, the interdigital transducer receiving the reflected surface acoustic waves, and the return signal, responsive to each reflected surface acoustic waves.

Abstract: A surface acoustic wave (SAW) device package and method for packaging a SAW device provide a surface excited device having a small footprint, low cost and fabricated according to a unique manufacturing process. A substrate including a SAW active area on a first side is bonded to another similar sized substrate with a space sufficient to allow the propagation of the SAW on a top surface of the substrate. The two substrates have similar thermal expansion coefficients such that stress from the sealing process is minimized. The two substrates are sealed using either a low melting point glass or an organic compound such that conductive pathways exist through the seal allowing the internal device to access an external electrical connection.

Abstract: An apparatus and method for generating piecewise linear phase transitions during a phase transition interval of a first signal to control controlling the phase/frequency of a second signal. The initiation point, duration and shaping parameters of the piecewise linear phase transitions are selected to control adjacent channel emissions in the second signal.