Abstract: A Lorentz force-driven mechanical resonator apparatus that utilizes a high-Q resonant structure as both a mixing device and a high-Q bandpass filter. Specifically, an external time varying, but quasistatic, magnetic field is applied to the resonating device while simultaneously running a time varying electrical current through the device. The resulting Lorentz force (I×B) is proportional to the vector product of the electrical current in the bar (I) and the external magnetic field (B). Integrating such a resonant device with a magnetic field coil produces the functionality of an ideal radio frequency (RF) mixer coupled with a high-Q intermediate frequency (IF) filter. Wide tunability provides the capability to scan, or even step, an array of filters having very narrow bandwidths via a common local oscillator to a desired frequency range.

Abstract: A Lorentz force-driven mechanical resonator apparatus that utilizes a high-Q resonant structure as both a mixing device and a high-Q bandpass filter. Specifically, an external time varying, but quasistatic, magnetic field is applied to the resonating device while simultaneously running a time varying electrical current through the device. The resulting Lorentz force (I×B) is proportional to the vector product of the electrical current in the bar (I) and the external magnetic field (B). Integrating such a resonant device with a magnetic field coil produces the functionality of an ideal radio frequency (RF) mixer coupled with a high-Q intermediate frequency (IF) filter. Wide tunability provides the capability to scan, or even step, an array of filters having very narrow bandwidths via a common local oscillator to a desired frequency range.

Abstract: A vehicular traffic sensor capable of measuring traffic speed and volume in all weather conditions and at a low installed cost. The sensor makes use of multi-path interference of ambient radio frequency (RF) signals. The ambient RF signals can be, for example, control signals constantly transmitted by cellular telephone base stations. As vehicles travel along the roadway, they reflect RF signals in all directions. An antenna mounted near the side of the road will detect signals from the transmitter and signals reflected off the vehicle. Variations in the amplitude of the combination of the two signals can be processed using a method that allows the sensor to determine traffic speed and volume. This information can then be sent directly to a traffic management center. This provides an inexpensive sensor for wide-area traffic monitoring.

Abstract: In a suspension control comprising a damper having a valve switchable at frequencies within a desired activation frequency range between high and low damping modes, an unfiltered damper signal is repeatedly derived from vehicle suspension related variables at a range significantly greater than the desired activation frequency range. An output filter derives a filtered damper signal from each successive binary actuator force signal by (1) resetting a timer each time the unfiltered damper signal changes value, (2) causing the filtered damper signal to be the same value as the unfiltered damper signal while the timer is inactive, and (3) maintaining the filtered damper signal value unchanged while the timer is active. The damper is controlled in response to the filtered damper signal, whereby unnecessary high frequency switching of the valve is reduced but the damper responds without unnecessary delay to signals within the desired activation frequency range.