Abstract: An ultrasound sensor includes a frame, wherein the frame includes an outer perimeter, an inner perimeter, and a midsection, wherein the midsection extends across the inner perimeter. The sensor further includes two or more transducer elements, wherein the two or more transducer elements are located within the inner perimeter, and include one or more membranes that include a bottom portion that includes a first piezoelectric layer and second piezoelectric layer, wherein the two or more transducer elements are each separated from the midsection, wherein the two or more transducer elements are configured to each activate a transmit mode and receive mode, wherein the transmit mode is configured to transmit a signal and the receive mode is configured to receive a signal, wherein a first transducer element activates the transmit mode when a second transducer element does not activate the transmit mode.

Abstract: An ultrasound sensor includes a frame, wherein the frame includes an outer perimeter, an inner perimeter, and a midsection, wherein the midsection extends across the inner perimeter. The sensor further includes two or more transducer elements, wherein the two or more transducer elements are located within the inner perimeter, and include one or more membranes that include a bottom portion that includes a first piezoelectric layer and second piezoelectric layer, wherein the two or more transducer elements are each separated from the midsection, wherein the two or more transducer elements are configured to each activate a transmit mode and receive mode, wherein the transmit mode is configured to transmit a signal and the receive mode is configured to receive a signal, wherein a first transducer element activates the transmit mode when a second transducer element does not activate the transmit mode.

Abstract: An ultrasound transducer of a vehicle system includes a support member that attaches to and connects to the bottom portion of a membrane of the ultrasound transducer and supports the membrane, wherein the support member includes one or more cantilevers with a first end attaching to the membrane and a second end attaching to a support portion of the support member that attaches to the substrate, wherein the cantilever extends across and floats above the substrate, wherein the first end of the cantilever includes a stub extending away from a surface of the cantilever, wherein the stub extends away from the surface without contacting the substrate, wherein the one or more cantilevers includes one or more piezoelectric layers on the surface of the cantilever.

Abstract: An ultrasound transducer of a vehicle system, comprising a membrane configured to vibrate to generate an ultrasound when voltage is applied and further configured to vibrate in an out-of-plane movement, wherein the membrane includes a first piezoelectric film at a center of the membrane, a supporting member including a second piezoelectric film, the supporting member supporting and surrounding the membrane, wherein in response to a translation of motion or actuation from the membrane, the supporting member mode does not move when there is the out-of-plane movement from the membrane.

Abstract: An ultrasound transducer, wherein the ultrasound transducer includes a membrane including a top portion and a bottom portion, wherein the membrane is configured to vibrate and generate an ultrasound in response to voltage applied the transducer, wherein the membrane includes a perimeter including a plurality of sides and a top surface and a bottom surface with one or more feet extending away from the bottom surface; and a support member that attaches to and connects to the membrane and supports the membrane, wherein the support member includes one or more platforms extending to and attaching to the membrane and a substrate, wherein a first end of the platform connects to the membrane and includes a support portion, wherein the support portion away from the platform, wherein the platform includes the one or more piezoelectric layers, wherein the one or more platforms support and surround the membrane.

Abstract: An imaging system for low-power and low data-rate applications is provided. The imaging system comprises a pixel array having a plurality of photosensitive elements (pixels) divided into a plurality of groups of photosensitive elements (super pixels). An image processor is operably connected to the pixel array and configured to selectively operate each group of photosensitive elements in either (i) a high resolution mode in which the pixel array outputs readout voltages corresponding to all of the photosensitive elements in the respective group of photosensitive elements or (ii) a low resolution mode in which the pixel array outputs readout voltages corresponding to only a subset of the photosensitive elements in the respective group of photosensitive elements. Groups of photosensitive elements corresponding to detected motion in each image frame are operated in the high resolution mode, while the remaining groups of photosensitive elements are operated in the low resolution mode.

Abstract: A radio frequency (RF) power combiner includes a first port with a first inverting input and a first non-inverting input, a second port with a second inverting input and a second non-inverting input, a first stabilization line coupled between the first non-inverting input and second non-inverting input, and a second stabilization line coupled between the first inverting input and the second inverting input.

Abstract: An imaging system for low-power and low data-rate applications is provided. The imaging system comprises a pixel array having a plurality of photosensitive elements (pixels) divided into a plurality of groups of photosensitive elements (super pixels). An image processor is operably connected to the pixel array and configured to selectively operate each group of photosensitive elements in either (i) a high resolution mode in which the pixel array outputs readout voltages corresponding to all of the photosensitive elements in the respective group of photosensitive elements or (ii) a low resolution mode in which the pixel array outputs readout voltages corresponding to only a subset of the photosensitive elements in the respective group of photosensitive elements. Groups of photosensitive elements corresponding to detected motion in each image frame are operated in the high resolution mode, while the remaining groups of photosensitive elements are operated in the low resolution mode.

Abstract: A capacitive transducer and a readout circuit for processing a signal from a capacitive transducer. The readout circuit includes a high gain circuit element, two summing amplifiers and two feedback path. The high gain circuit element generates an amplified transducer signal, and the summing amplifiers sum the amplified transducer signal with a positive reference voltage and the negative reference voltage, respectively, to generate a first summation signal and a second summation signal. The feedback paths feed back the summation signals to the transducer. Output circuitry generates an output signal based on the summation signals. The high gain circuit element can be a switched capacitor integrator. The output circuitry can generates the output signal based on the first and second summation signals.

Abstract: A system and method are disclosed for automatically calibrating capacitive transducers to neutralize feed-through capacitance using linear actuation. The method includes starting with an initial neutralization capacitance, applying no electrostatic force and two known electrostatic forces to a proof mass of the transducer, recording the transducer output changes due to the applied forces; and determining how to revise neutralization capacitance based on the changes. The method can use a binary search to find a final neutralization capacitance providing the best linearity. The method can include comparing the final linearity to a threshold linearity. The electrostatic forces can be applied using a charge control method where the electrostatic force is a linear function of the actuation duration. The linear actuation can be used for continuous self-test of capacitive sensors.

Abstract: A pseudo-differential accelerometer resistant to EMI is disclosed that includes a device with a sensor core connected to an integrated circuit including a chopper, differential amplifier, and dummy core. The chopper swaps input to output connections during different states. The dummy core is coupled to a dummy chopper input. Three bond wires coupling the sensor output to a sensor chopper input, a first chopper output to a first sensor input, and a second chopper output to a second sensor input can connect the sensor and integrated circuit. The device can include a dummy pad and dummy bond wire connecting the dummy pad to the dummy chopper input. This configuration requires four bond wires connecting the sensor and integrated circuit. A neutralization core can be connected to the sensor chopper input. The chopper can change states to smear noise across a wide range, or away from a band of interest.

Abstract: A system and method are disclosed for automatically calibrating capacitive transducers to neutralize feed-through capacitance using linear actuation. The method includes starting with an initial neutralization capacitance, applying no electrostatic force and two known electrostatic forces to a proof mass of the transducer, recording the transducer output changes due to the applied forces; and determining how to revise neutralization capacitance based on the changes. The method can use a binary search to find a final neutralization capacitance providing the best linearity. The method can include comparing the final linearity to a threshold linearity. The electrostatic forces can be applied using a charge control method where the electrostatic force is a linear function of the actuation duration. The linear actuation can be used for continuous self-test of capacitive sensors.

Abstract: A differential capacitive transducer system is disclosed that includes first and second capacitive cores and a chopping system. The first core a first input coupled to a first capacitor, a second input coupled to a second capacitor, and a first output. The second core includes a third input coupled to a third capacitor, a fourth input coupled to a fourth capacitor, and a second output. The chopping system has first and fourth inputs coupled to positive signals, and second and third inputs coupled to negative signals. As the chopping system switches between high and low states, it couples the core inputs to different polarity signals reducing charge buildup. The different polarity signals can have substantially same magnitudes. Chopper clock and main clock frequencies can be selected to provide substantially zero average voltages at the core inputs. The system can include an integrator circuit and differential summing circuits.

Abstract: A capacitive sensor system and method resistant to electromagnetic interference is disclosed. The system includes a capacitive core, differential amplifier with inverting and non-inverting inputs, capacitive paths, and chopping system. Core can include inputs and outputs coupled to variable capacitors, and common nodes coupling variable capacitors. Capacitive paths couple core outputs to amplifier inputs. When chopping system is high, one polarity voltage is applied to core inputs, a first core output is coupled to the inverting input and a second core output is coupled to the non-inverting input. When the chopping system is low, opposite polarity voltage is applied to core inputs, and core output to amplifier input couplings are flipped. Capacitive paths can include bond wires. Chopping system can be varied between high and low at frequencies that smear noise away from a frequency band of interest, or that smear noise substantially evenly across a wide frequency range.

Abstract: A differential capacitive transducer system is disclosed that includes first and second capacitive cores and a chopping system. The first core a first input coupled to a first capacitor, a second input coupled to a second capacitor, and a first output. The second core includes a third input coupled to a third capacitor, a fourth input coupled to a fourth capacitor, and a second output. The chopping system has first and fourth inputs coupled to positive signals, and second and third inputs coupled to negative signals. As the chopping system switches between high and low states, it couples the core inputs to different polarity signals reducing charge buildup. The different polarity signals can have substantially same magnitudes. Chopper clock and main clock frequencies can be selected to provide substantially zero average voltages at the core inputs. The system can include an integrator circuit and differential summing circuits.

Abstract: A capacitive transducer and a readout circuit for processing a signal from a capacitive transducer. The readout circuit includes a high gain circuit element, two summing amplifiers and two feedback path. The high gain circuit element generates an amplified transducer signal, and the summing amplifiers sum the amplified transducer signal with a positive reference voltage and the negative reference voltage, respectively, to generate a first summation signal and a second summation signal. The feedback paths feed back the summation signals to the transducer. Output circuitry generates an output signal based on the summation signals. The high gain circuit element can be a a switched capacitor integrator. The output circuitry can generates the output signal based on the first and second summation signals.

Abstract: A capacitive sensor system and method resistant to electromagnetic interference is disclosed. The system includes a capacitive core, differential amplifier with inverting and non-inverting inputs, capacitive paths, and chopping system. Core can include inputs and outputs coupled to variable capacitors, and common nodes coupling variable capacitors. Capacitive paths couple core outputs to amplifier inputs. When chopping system is high, one polarity voltage is applied to core inputs, a first core output is coupled to the inverting input and a second core output is coupled to the non-inverting input. When the chopping system is low, opposite polarity voltage is applied to core inputs, and core output to amplifier input couplings are flipped. Capacitive paths can include bond wires. Chopping system can be varied between high and low at frequencies that smear noise away from a frequency band of interest, or that smear noise substantially evenly across a wide frequency range.

Abstract: Capacitive transducer systems are disclosed that reduce nonlinearities due to feedthrough capacitances or residual electrostatic forces. The systems can include a core with a first input coupled to a first variable capacitor, a second input coupled to a second variable capacitor, and a core output coupled to a common node; an amplifier with input switchably coupled to common node and an output; a feedback path switchably coupling amplifier output to common node; and a main clock with first and second phases, that controls switches coupling system components. When clock is in first phase, first core input is coupled to reference voltage, second core input is coupled to negative reference voltage, and common node is coupled to amplifier output. When clock is in second phase, core inputs are grounded, and common node is coupled to amplifier input. The system can have single amplifier. Neutralization capacitor can cancel feedthrough and parasitic capacitances.

Abstract: Capacitive transducer systems are disclosed that reduce nonlinearities due to feedthrough capacitances or residual electrostatic forces. The systems can include a core with a first input coupled to a first variable capacitor, a second input coupled to a second variable capacitor, and a core output coupled to a common node; an amplifier with input switchably coupled to common node and an output; a feedback path switchably coupling amplifier output to common node; and a main clock with first and second phases, that controls switches coupling system components. When clock is in first phase, first core input is coupled to reference voltage, second core input is coupled to negative reference voltage, and common node is coupled to amplifier output. When clock is in second phase, core inputs are grounded, and common node is coupled to amplifier input. The system can have single amplifier. Neutralization capacitor can cancel feedthrough and parasitic capacitances.

Abstract: A system and method are disclosed for automatically calibrating capacitive transducers to neutralize feed-through capacitance using linear actuation. The method includes starting with an initial neutralization capacitance, applying no electrostatic force and two known electrostatic forces to a proof mass of the transducer, recording the transducer output changes due to the applied forces; and determining how to revise neutralization capacitance based on the changes. The method can use a binary search to find a final neutralization capacitance providing the best linearity. The method can include comparing the final linearity to a threshold linearity. The electrostatic forces can be applied using a charge control method where the electrostatic force is a linear function of the actuation duration. The linear actuation can be used for continuous self-test of capacitive sensors.