Abstract: Method embodiments are disclosed to determine arrival directions of electromagnetic signals that have a known signal frequency and a known guided signal wavelength. These methods are realized with an antenna configured to define, at the signal frequency, at least one metamaterial cell between first and second signal ports. They then include the step of rotating the antenna until the differential power from the first and second signal ports is substantially zero and then determining the arrival direction as a normal to the metamaterial cell. In other method embodiments, the antenna is stationary and a differential power is determined wherein the differential power is defined as the difference between received powers from the first and second ports. The arrival direction of electromagnetic signals are then determined from the differential power.

Abstract: Method embodiments are disclosed to determine arrival directions of electromagnetic signals that have a known signal frequency and a known guided signal wavelength. These methods are realized with an antenna configured to define, at the signal frequency, at least one metamaterial cell between first and second signal ports. They then include the step of rotating the antenna until the differential power from the first and second signal ports is substantially zero and then determining the arrival direction as a normal to the metamaterial cell. In other method embodiments, the antenna is stationary and a differential power is determined wherein the differential power is defined as the difference between received powers from the first and second ports. The arrival direction of electromagnetic signals are then determined from the differential power.

Abstract: A vanadium dioxide front-end advanced shutter device. The electronic shutter device is designed to protect receiver front-ends and other sensitive circuits from HPM pulse events such as HPM weapons, directed energy weapons, or EMPs. The shutter incorporates a transition material such as thin-film vanadium oxide (VOX) materials that exhibit a dramatic change in resistivity as their temperature is varied over a narrow range near a known critical temperature. A high-energy pulse causes ohmic heating in the shutter device, resulting in a state change in the VOX material when the critical temperature is exceeded. During the state change the VOX material transitions from an insulating state (high resistance) to a reflective state (low resistance). In the insulating state, the shutter device transmits the majority of the signal. In the reflective state, most of the signal is reflected and prevented from passing into electronics on the output side of the shutter device.

Abstract: A vanadium dioxide front-end advanced shutter device. The electronic shutter device is designed to protect receiver front-ends and other sensitive circuits from HPM pulse events such as HPM weapons, directed energy weapons, or EMPs. The shutter incorporates a transition material such as thin-film vanadium oxide (VOX) materials that exhibit a dramatic change in resistivity as their temperature is varied over a narrow range near a known critical temperature. A high-energy pulse causes ohmic heating in the shutter device, resulting in a state change in the VOX material when the critical temperature is exceeded. During the state change the VOX material transitions from an insulating state (high resistance) to a reflective state (low resistance). In the insulating state, the shutter device transmits the majority of the signal. In the reflective state, most of the signal is reflected and prevented from passing into electronics on the output side of the shutter device.

Abstract: A method and apparatus for changing the polarization of an input signal includes propagating a polarized input signal having orthogonal E-field components by at least one surface each having a respective surface impedance and varying at least one of the surface impedances to shift the phase of one of the components independently from the other so that the polarity of said input signal is changed. Bi-directional propagation is achieved by rotating polarity in one direction but not the other.

Abstract: An integrated, variable gain microwave frequency power amplifier comprises a number of individual amplifier stages which contain microwave frequency active devices. Each stage is fed with a common input signal, and the individual stage outputs are connected to respective micro-electromechanical (MEM) switches which, when closed, connect the individual outputs together to form the power amplifier's output. The power amplifier's gain is determined by the number of outputs connected together. The preferred switch provides low insertion loss and excellent electrical isolation, enabling a number of amplifier stages to be efficiently interconnected to provide a wide dynamic range power amplifier. The switches are preferably integrated on a common substrate with the active devices, eliminating the need for wire bonds and reducing parasitic capacitances.

Abstract: A continuous wave Doppler radar system having a transmitter module and a receiver module is provided for automotive vehicles. Each module includes an antenna system, including a horn, a lens, and a waveguide system, which is attached to a monolithic microwave integrated circuit (MMIC) chip that provides all necessary electronic functions. Each MMIC chip may be attached to a metal base heat sink, which may be conveniently connected to a base plate heat sink that holds the entire radar assembly. The transmitter module includes a voltage controlled oscillator (VCO) that generates a VCO frequency signal which is amplified and switched sequentially to three multiplier chains for transmission in three different directions. Each transmit signal is taken off the MMIC chip by a dielectric waveguide and directed to the antenna system. The receiver module includes three receivers that are selected sequentially to provide a beam azimuth scanning function.

Abstract: A monolithic quasi-optic amplifier is provided for co-linear beam propagation in the millimeter wave frequency range (30-300 GHz). The amplifier comprises a multiplicity of unit cells that act as nearly independent amplifiers. Each unit cell includes a GaAs transistor, a slot antenna, a patch antenna, a microstrip line, and a DC bias provided by a ground plane that routes non-radiating transmission lines without interference. The slot antennas on GaAs provide preferential directionality in receiving the input waves. A vertically polarized input wave couples energy into each unit cell through the slots in the ground plane, through the microstrip lines, and to the base of each transistor. After amplification by the transistors, the signal is fed to the patch antennas, which generate a horizontally polarized output wave. The size of each patch antenna, which is determined by the operating frequency, is approximately 1 mm by 1 mm in GaAs at 44 GHz.

Abstract: Thin electrodes are coupled to a resistive film on an active semiconductive layer to form a gapless gate CCD (GGCCD). The active layer is formed ona semi-insulating substrate, and the resistive film is joined to the active layer by a Schottky barrier. The thin electrode coupled to the resistive film induce fringing fields near the surface to provide high speed charge transport and permit the use of a thin active layer.

Abstract: A miniaturized probe is provided for making contact with test probe pads on an integrated circuit. The probe tips are precisely positioned on the underside of a microwave substrate board. Short wires extend through a hole in the insulating board and connect the probe tips to a conductive line on the topside of the microwave substrate board. The wires are imbedded in a potting compound which also holds the probe tips. Precise location of the probe tips is accomplished during fabrication of the probe by using depressions etched in a substrate as a mold and depositing metal in these depressions using photoresist and deposition techniques.

Abstract: A monolithic microwave amplifier fabricated on a GaAs substrate utilizes MESFETs to provide both gain and impedance matching. The source of a first MESFET is connected to an input terminal of the amplifier and its drain is connected to an interstage matching network. The gate of a second MESFET is connected to the output of the interstage matching network and its source is connected to the output terminal of the amplifier. Suitable voltages are applied to the MESFETs to bias the devices appropriately. The gate of the first MESFET and the drain of the second MESFET are connected in common with the grounds of the amplifier's input and output ports. In a second embodiment, additional gain is obtained by providing a third MESFET with a common source connection between the first and second MESFETs.

Abstract: An analog transversal filter includes a charge transfer delay line, including a plurality of cells for storing electrical charge, and a multiphase clock to transfer electrical charge from cell to cell through the delay line. A plurality of injection electrodes are connected to predetermined ones of the cells to sample an electrical signal, weight the signal sample a predetermined amount, and inject a charge packet representing the weighted signal sample into the cell. An output electrode collects and sums the charge packets transferred through the delay line. In another embodiment, the filter includes a plurality of charge transfer delay lines, with a plurality of cells for storing electrical charge in each delay line.