Abstract: A system and method for determining loading of a filter having a first dielectric constant with a material having a different dielectric constant, is disclosed. The filter is contained within a metallic container forming a microwave cavity, and microwave or RF energy is created within the cavity and changes in the cavity microwave response are monitored. The changes in cavity microwave response are related to filter loading. In a preferred embodiment, the microwave energy includes multiple cavity modes thereby allowing determination of spatial distribution of the contaminant material loading. In one embodiment, the microwave cavity response includes a shift in frequency of a resonant mode. Alternatively, the microwave cavity response includes a shift in quality factor Q of a resonant mode. The microwave cavity response may include a shift in amplitude or peak width of the microwave's signal at resonance.

Abstract: A particulate filter control system and method for controlling the same is disclosed. The particulate filter load monitoring system may transmit radio frequency signals through the resonant cavity and filter medium across a frequency range sufficient to generate more than one resonant mode. The system may contain additional sensors for monitoring additional exhaust characteristics and parameters. Further, a control unit may be configured to determine the amount of material accumulated in the particulate filter, detect failures and malfunctions of the exhaust after-treatment system and its associated components, and initiate an action based on the amount of material accumulated in the particulate filter, the determination of a system failure or malfunction, or input from one or more exhaust sensors.

Abstract: A system and method for determining loading of a filter having a first dielectric constant with a material having a different dielectric constant, is disclosed. The filter is contained within a metallic container forming a microwave cavity, and microwave or RF energy is created within the cavity and changes in the cavity microwave response are monitored. The changes in cavity microwave response are related to filter loading. In a preferred embodiment, the microwave energy includes multiple cavity modes thereby allowing determination of spatial distribution of the contaminant material loading. In one embodiment, the microwave cavity response includes a shift in frequency of a resonant mode. Alternatively, the microwave cavity response includes a shift in quality factor Q of a resonant mode. The microwave cavity response may include a shift in amplitude or peak width of the microwave's signal at resonance.

Abstract: A particulate filter control system and method for controlling the same is disclosed. The particulate filter load monitoring system may transmit radio frequency signals through the resonant cavity and filter medium across a frequency range sufficient to generate more than one resonant mode. The system may contain additional sensors for monitoring additional exhaust characteristics and parameters. Further, a control unit may be configured to determine the amount of material accumulated in the particulate filter, detect failures and malfunctions of the exhaust after-treatment system and its associated components, and initiate an action based on the amount of material accumulated in the particulate filter, the determination of a system failure or malfunction, or input from one or more exhaust sensors.

Abstract: A system and method for determining loading of a filter having a first dielectric constant with a material having a different dielectric constant, is disclosed. The filter is contained within a metallic container forming a microwave cavity, and microwave or RF energy is created within the cavity and changes in the cavity microwave response are monitored. The changes in cavity microwave response are related to filter loading. In a preferred embodiment, the microwave energy includes multiple cavity modes thereby allowing determination of spatial distribution of the contaminant material loading. In one embodiment, the microwave cavity response includes a shift in frequency of a resonant mode. Alternatively, the microwave cavity response includes a shift in quality factor Q of a resonant mode. The microwave cavity response may include a shift in amplitude or peak width of the microwave's signal at resonance.

Abstract: A particulate filter control system and method for controlling the same is disclosed. The particulate filter load monitoring system may transmit radio frequency signals through the resonant cavity and filter medium across a frequency range sufficient to generate more than one resonant mode. The system may contain additional sensors for monitoring additional exhaust characteristics and parameters. Further, a control unit may be configured to determine the amount of material accumulated in the particulate filter, detect failures and malfunctions of the exhaust after-treatment system and its associated components, and initiate an action based on the amount of material accumulated in the particulate filter, the determination of a system failure or malfunction, or input from one or more exhaust sensors.

Abstract: Method for determining loading of a filter. The filter has a first dielectric constant. The filter becomes loaded with contaminant material that has a second dielectric constant. The filter, such as a diesel particulate filter, is contained within a metallic enclosure forming a microwave cavity. The method includes establishing microwave energy in the cavity and monitoring changes in the cavity microwave response, the changes being related to filter loading.

Abstract: Method for determining loading of a filter. The filter has a first dielectric constant. The filter becomes loaded with contaminant material that has a second dielectric constant. The filter, such as a diesel particulate filter, is contained within a metallic enclosure forming a microwave cavity. The method includes establishing microwave energy in the cavity and monitoring changes in the cavity microwave response, the changes being related to filter loading.

Abstract: An identification/security tag system, including miniaturized tags which can be readily concealed, utilizes a concept of "electronic" Doppler shifting to generate a frequency shifted signal in response to an interrogation signal. The frequency shifted signal is used to identify individual tags. The implementation of electronic Doppler shifting permits the utilization of conventional police/sport radar guns as a combined transmitter and receiver unit, thereby greatly reducing the expense of the system. The high frequency operation of the system permits size of the tag to be significantly reduced with respect to the size of tags used in conventional tag systems. Rectenna circuitry is further employed to eliminate the need for an active power supply in the tag in some applications.

Abstract: A system and method for "power beaming" energy from a source at high frequencies and rectifying such energy to provide a source of DC energy is disclosed. The system operates at a frequency of at least 10 GHz and incorporates a rectenna array having a plurality of rectenna structures that utilize circuit elements formed with microstrip circuit techniques. Each rectenna element is associated with a resonating cavity structure.

Abstract: A system and method for power beaming energy from a source at high frequencies and rectifying such energy to provide a source of DC energy is disclosed. The system operates at a frequency of at least 10 GHz and incorporates a rectenna array having a plurality of rectenna structures that utilize circuit elements formed with microstrip circuit techniques.

Abstract: This invention relates to generation of a Artificial Ionospheric Mirror (AIM), or a plasma layer in the atmosphere. The AIM is used like the ionosphere to reflect RF energy over great distances. A tiltable AIM is created by a heater antenna controlled in phase and frequency. The heater antenna phase shift scans a beam to paint a plasma layer. Frequency is changed to refocus at continually higher altitudes to tilt the plasma layer.