Abstract: An apertured metallic ground plate antenna element having a high input impedance is driven from a lower impedance input transmission line by means of an exciter that provides broadband impedance transformation. The input transmission line is divided into two higher impedance feed lines that feed two parallel plate transmission lines. The parallel plate transmission lines are positioned in close proximity to the element aperture and are oriented to provide antenna excitation in series.

Abstract: A standard cavity, Q switched laser is used to initiate and sustain submicrosecond pulses in a long laser. Short pulses from the standard cavity laser are directed onto the remote reflector of a long laser and are then reflected back through the lasing material of the long laser. Properly timed activation of the long laser lasing material causes amplification and oscillation of the pulses in the long laser cavity. Beam expanding telescopes are used to focus the laser pulses on the long laser's remote reflector.

Abstract: Digital filter auto-adjustment to variations in input signals is achieved by normalizing the output of the second of two substantially identical series-connected digital filter stages and subtracting the normalized output of the second filter stage from its input to provide a measure of filter signal residue power. Deviations of the signal residue power from the preset limits of a signal residue power standard are detected and signals responsive thereto are used to appropriately adjust variable bandwidth constants in both filter stages.

Abstract: A circuit is disclosed that detects radiation transients and provides a clamping signal in response to each transient. The clamping signal is present from the time the transient rises above a given threshold level and for a known duration thereafter. The system includes radiation sensors, a blocking oscillator that generates a pulse in response to each sensor signal, and an output pulse duration control circuit. The oscillator pulses are fed simultaneously to the output pulse duration control circuit and to an OR gate, the output of which comprises the system output. The output pulse duration is controlled by the time required to magnetize a magnetic core to saturation in first one direction and then the other.

Abstract: The alignment of a collimated light beam is monitored by diverting a sample portion of the beam through an auxiliary optical light beam transmission system which converts the sample portion into an annular collimated light beam and transmits it coaxially with the main beam. The annular beam is reflected back through its transmission system by a fixed reference annular mirror that permits the passage of the main beam through its aperture. The retransmitted annular beam is divided to sensors that detect its angular misalignment and lateral displacement as a true measure of main beam alignment relative to the fixed reference annular mirror. End to end main beam alignment is accomplished by servo controlled optical elements that respond to the outputs of these sensors and to the outputs of sensors that measure alignment of the main beam input.

Abstract: The input transducers of a multichannel surface acoustic wave device are electrically connected in a series or series-parallel circuit arrangement and are connected to a single channel electromagnetic wave transmission line through an inductor. The inductance value of the inductor is chosen such that minimum transducer insertion loss is achieved at the center frequency of the midband channel. The circuit arrangement is selected which achieves optimum coupling to the midband channel subject to the constraint that the insertion losses of all the remaining channels, measured at their respective center frequencies, lie at or near the above optimum value within an acceptable prespecified margin.