Abstract: An active artificial magnetic conductor comprising an array of unit cells, each unit cell comprising an electrically conductive patch that is connected with an electrically conductive patch of neighboring unit cell in a column of unit cells using a non-Foster negative inductor and having RF isolating plates or walls between rows of unit cells. These isolating plates or walls eliminate undesirable cross coupling between the non-Foster negative inductors. The electrically conductive patches may be formed by metallic patches preferably arranged in the 2D array of such patches. Each patch preferably has a rectilinear shape.

Abstract: Low cost millimeter wave imagers using two-dimensional focal plane arrays based on backward tunneling diode (BTD) detectors. Two-dimensional focal arrays of BTD detectors are used as focal plane arrays in imagers. High responsivity of BTD detectors near zero bias results in low noise detectors that alleviate the need for expensive and heat generating low noise amplifiers or Dicke switches in the imager. BTD detectors are installed on a printed circuit board using flip chip packaging technology and horn antennas direct the waves toward the flip chip including the BTD detectors. The assembly of the horn antennas, flip chips, printed circuit board substrate, and interconnects together work as an imaging sensor. Corrugated surfaces of the components prevent re-radiation of the incident waves.

Abstract: Low cost millimeter wave imagers using two-dimensional focal plane arrays based on backward tunneling diode (BTD) detectors. Two-dimensional focal arrays of BTD detectors are used as focal plane arrays in imagers. High responsivity of BTD detectors near zero bias results in low noise detectors that alleviate the need for expensive and heat generating low noise amplifiers or Dicke switches in the imager. BTD detectors are installed on a printed circuit board using flip chip packaging technology and horn antennas direct the waves toward the flip chip including the BTD detectors. The assembly of the horn antennas, flip chips, printed circuit board substrate, and interconnects together work as an imaging sensor. Corrugated surfaces of the components prevent re-radiation of the incident waves.

Abstract: A multi-level gas inflator for an air bag or other safety device, comprising an elongated pressure vessel having a primary gas generant portion with a first open end and a secondary portion with a second open end. The primary gas generant portion has a primary ignition device and primary gas generating energetics disposed therein. The primary ignition device is mounted on and closes the pressure vessel at the first open end thereof. The secondary portion may have a secondary ignition device and secondary gas generating energetics disposed therein. The secondary ignition device may be mounted on the pressure vessel at the second open end thereof. A suitable gas under a predetermined pressure is present in the primary and secondary portions. One or more separate dividers or divider walls are disposed within the midportion of the pressure vessel to separate the primary and secondary portions.

Abstract: A method and apparatus for creating uniform heating of an microwave absorptive target. A circularly polarized waveguide mode is created that promotes uniform heating of the microwave absorptive target by rotating a propagated non-uniform field pattern around a central axis of a cylindrical cavity or waveguide. In the process of rotating the field pattern, hot and cold spots in the field pattern are averaged out over time.

Abstract: A method for guiding waves over objects, a method for improving a performance of an antenna, and a method for improving a performance of a radar are disclosed. The methods disclosed teach how an impedance structure can be used to guide waves over objects.

Abstract: A method and apparatus for creating uniform heating of an microwave absorptive target. A circularly polarized waveguide mode is created that promotes uniform heating of the microwave absorptive target by rotating a propagated non-uniform field pattern around a central axis of a cylindrical cavity or waveguide. In the process of rotating the field pattern, hot and cold spots in the field pattern are averaged out over time.

Abstract: A diesel particulate filter including a microwave-absorbing target within a waveguide cavity. The cavity accepts microwave-frequency electromagnetic radiation through input couplers 90 degrees out of phase with each other to excite circular polarization heating modes. Through excitation of circularly polarized modes, heating patterns are time-averaged azimuthally to smooth out the hot and cold spots, thereby providing greater uniformity relative to heating patterns for corresponding linearly polarized modes.

Abstract: A method and apparatus for creating uniform heating of an microwave absorptive target. A circularly polarized waveguide mode is created that promotes uniform heating of the microwave absorptive target by rotating a propagated non-uniform field pattern around a central axis of a cylindrical cavity or waveguide. In the process of rotating the field pattern, hot and cold spots in the field pattern are averaged out over time.

Abstract: A dual-band monopole antenna includes a ground plane. A metal plate is located a first distance from the ground plane and includes first and second portions connecting to form a first angle therebetween. A slot is formed in the metal plate that isolates a center portion of the metal plate. The dual-band monopole antenna communicates first radio frequency (RF) signals in a first RF band and second RF signals in a second RF band. A feed tab contacts an outer surface of the metal plate and is located the first distance from the ground plane. The first RF signals and the second RF signals are vertical polarized signals. The dual-band monopole antenna produces a radiation pattern that is omnidirectional in the azimuth plane and vertically polarized in a horizontal plane. The first RF band and the second RF band are independently tuned.

Abstract: A low-profile dual-band antenna includes a ground plane. An “E”-shaped metal plate is located a first distance from the ground plane and includes first and second outer extensions and an inner extension of the metal plate. A feed tab connects the inner extension and the ground plane. A shorting tab connects the inner extension and the ground plane. The low-profile dual-band antenna communicates first radio frequency (RF) signals in a first RF band and second RF signals in a second RF band. The first RF signals and the second RF signals are vertical polarized signals. The low-profile dual-band antenna produces a radiation pattern that is omnidirectional in the azimuth plane and vertically polarized in a horizontal plane when communicating the first RF signals and the second RF signals. The first RF band and the second RF band can be independently tuned.