Abstract: A method is provided for calibrating a device under calibration (DUC) for optimizing performance of the DUC.

Abstract: A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective direction coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed to receive reflected microwave illumination reflected from the position on the target. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.

Abstract: An apparatus and method for adapting a power amplifier to a variable load includes comparing the actual output power to the expected output power, modifying a drive signal to the power amplifier, measuring the value of at least one electrical parameter, determining the difference between the measured value and a predetermined value, and periodically adjusting the drive signal according to the difference. The parameters modified include, but are not limited to, the power delivered to the input of the power amplifier, the DC power supply voltage to any stage of the power amplifier, and the current setting bias values.

Abstract: The system comprises a first beatable signal source, a second beatable signal source, a phase reference signal source and a receiver. The first beatable signal source and the second beatable signal source are located at the source location; the receiver is located at the receiver location. The phase reference signal source is operable to generate a phase reference signal. The first beatable signal source is operable to transmit a first beatable signal. The second beatable signal source is spatially offset from the first beatable signal source in a reference direction, and is operable to transmit a second beatable signal differing in frequency from the first beatable signal by a frequency difference. The first beatable signal and the second beatable signal collectively have a phase relationship with the phase reference signal.

Abstract: A radio frequency (RF) amplifier includes an RF drive adjust circuit adapted to receive an input signal and adjust at least one of the amplitude and phase thereof to output a drive-adjusted input signal; a gain element adapted to amplify the drive-adjusted input signal and to output an amplified signal; and a dynamic impedance transformer adapted to receive the amplified signal, to output an output signal, and to transform a load impedance presented to the gain element by a load in accordance with a desired amplitude of an envelope of the output signal.

Abstract: A radio frequency (RF) amplifier includes an RF drive adjust circuit adapted to receive an input signal and adjust at least one of the amplitude and phase thereof to output a drive-adjusted input signal; a gain element adapted to amplify the drive-adjusted input signal and to output an amplified signal; and a dynamic impedance transformer adapted to receive the amplified signal, to output an output signal, and to transform a load impedance presented to the gain element by a load in accordance with a desired amplitude of an envelope of the output signal.

Abstract: A microwave imaging system uses microwave radiation provided by a microwave source to image targets. The system includes an array of antenna elements that are capable of being programmed with a respective transmission coefficient to direct the microwave illumination from the microwave source toward a position on the target. The antenna elements are further capable of being programmed with a respective additional transmission coefficient to receive reflected microwave illumination reflected from the position on the target and direct the reflected microwave illumination towards a microwave receiver. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the target. Multiple beams can be directed towards the target to obtain corresponding pixel values for use by the processor in constructing the image.

Abstract: A reflectarray utilizes switching devices with non-ideal impedance characteristics to vary the impedance of reflecting elements. The antennas of the reflecting elements are configured as a function of the impedance of the non-ideal switching devices to provide optimal phase-amplitude performance. In particular, the antennas are configured such that the impedance of each antenna is proportional to the square root of the impedance of the non-ideal switching devices when in an on state and when in an off state.

Abstract: A security inspection system uses microwave radiation to image targets on a human subject or other item. The system includes an array of antenna elements that are programmable with a respective phase delay to direct a beam of microwave illumination toward a target on the human subject or item. The antenna elements are further capable of receiving reflected microwave illumination reflected from the target. A processor is operable to measure an intensity of the reflected microwave illumination to determine a value of a pixel within an image of the human subject or item. Multiple beams can be directed towards the human subject or item to obtain corresponding pixel values for use by the processor in constructing the image.

Abstract: A method for planarizing a substrate surface having a non-planar surface topography comprises forming a material layer over the substrate, the material layer having a surface topography, determining the surface topography of the material layer, and forming a mask using information relating to the surface topography of the material layer. The mask defines portions of averaging regions of the material layer for selective removal to equalize the averaging regions in average height, the averaging regions having a maximum dimension. The material layer is etched using the mask, and a planarizing layer is formed over the substrate surface. The planarizing layer provides a low-pass lateral filtering effect characterized by a length greater than the maximum dimension of the averaging region.