Abstract: A Schottky barrier semiconductor device wherein the semiconductor is gallium arsenide and the metal electrode is tantalum, passivated by formation of native oxides after the metal-semiconductor junction is made. Tantalum acts as a diffusion shield, enabling use of gold as a direct contact on the electrode.

Abstract: A tuning compensation device to reduce post-tuning frequency drift in voltage controlled oscillators, comprising a thermoelectric element, such as a wafer of doped semiconductor material, in contact with the junction of a tuning element, such as a varactor diode, to produce a correction to the control voltage and thereby compensate for thermally induced frequency drift.

Abstract: A mesa semiconductor device, including a metal film conductor located on the upper surface of the device about the base of the mesa to reduce skin effect loss.

Abstract: In order to detect the identification marks on an exposed transparent card in a stack of similar cards, the identification marks on the exposed card are illuminated by polarized light that is incident at an angle greater than the polarizing angle of the transparent material of the cards. The high angle of incidence and the polarization of the incident light reduce the transmission of light through the exposed card, and thereby reduce the illumination and probability of detection of identification marks on a card adjacent the exposed card.

Abstract: Microwave devices for power conversion between harmonically related frequencies, using an oversized cavity and antenna means to provide the required coupling to a varactor therein.

Abstract: A generally disc shaped tool shaft holder with an opening at its center adapted to accept a tool shaft, and a plurality of openings about its periphery, each of which is designed to accept a lever arm. The holder is divided into an inner and an outer section which may be detached from one another. The outer section may be used with a number of different inner sections, each of which is adapted for use with a particular tool.

Abstract: An adaptive signal processor including a network that adjusts itself on the basis of power maximization to resolve a raw composite input signal structure at least approximately into its separate statistically independent self-correlated components, or eigenvectors, and automatic gain control circuits for equalizing the power levels, or eigenvalues, of these components. The equalized component signals may be used as inputs to conventional adaptive systems, providing improved settling speed and dynamic range, or may in some cases be used directly, without further adaptive processing.

Abstract: Apparatus for transferring a designated card or card-like article such as a microfiche into or out of a stack of similar cards by producing a separation in the stack at a selected location with a stream of air and moving the designated card into or out of the separation with a vacuum pickup arm. The selected stack location is verified by reading means located outside of the stack and directed at retroreflective marks on the card exposed by the separation.

Abstract: Radiator slots spaced along a main waveguide are coupled to respective array element ports through branch waveguides proportioned to provide equal length transmission paths from a common feed port on the main waveguide.

Abstract: A variable frequency voltage controlled oscillator is tuned to a selected frequency by applying a varying voltage to the control port of the oscillator to sweep the oscillator signal through a frequency range which includes the frequency of a reference frequency source. The value of the varying voltage is stored at the instant the oscillator frequency coincides with the frequency of the reference source. A dc offset voltage is then added to the stored voltage to produce a sum voltage which is substituted for the varying voltage at the control port of the oscillator to tune the oscillator to the selected frequency. The offset voltage is equal to the difference in the control voltages at the selected and reference frequencies and may be determined from the oscillator control voltage characteristic.