Abstract: The application discloses a method and apparatus to apply pressure to a heated or weld region of a workpiece to relieve residual stress and distortion. In illustrated embodiments, heat is supplied via a probe that traverses a workpiece to heat a region of the workpiece. Pressure is applied to the heated region following the application of heat. In illustrated embodiments, pressure is supplied via a roller assembly, which is configured to traverse the workpiece to apply pressure to the heated or weld regions.

Abstract: Disclosed is an array antenna (10) that may be reconfigured to point in multiple directions. The array antenna includes a driven element (12) coupled to a transmission line (14) and a pair of passive elements (22) and (24). The passive elements (22) and (24) each include three antenna segments that are coupled together by a pair of optoelectronic switches (26) and (28), respectively. When the optoelectronic switches coupled to a particular passive element are closed the element functions as a reflector; when the switches are open, the element functions as a director. Other reconfigurable antennas are also disclosed, including antennas with reconfigurable gain and field pattern characteristics.

Abstract: Disclosed is an optically activated microwave switch (10) which includes a field-effect transistor (12) that is switched between conducting and nonconducting states by a photodiode (14) that is connected between the field-effect transistor gate and drain electrode and a photodiode (16) that is connected between the field-effect transistor gate and source electrode. The circuit is configured and arranged for switching unbiased sinusoidal microwave signals of a frequency as high as approximately 10 gigahertz. A cascade arrangement of switches (10) provides increased signal handling capability in situations in which a single switch cannot be employed. Monolithic integrated circuit realizations of both single stage and cascaded stage arrangements are disclosed in which the semiconductor substrate is GaAs, the field-effect transistors are metal-semiconductor field-effect transistors and the photodiodes are interdigitated metal-semiconductor-metal devices.