Abstract: An electromagnetic reflector includes an antenna that receives an incoming signal and that transmits an outgoing signal. A three-port device, such as a circulator, has a first port electromagnetically coupled to the antenna. An RF circuit has an input that is electromagnetically coupled to the second port of the three-port device and an output that is electromagnetically coupled to the third port of the three-port device. The RF circuit changes at least one of a gain and a phase of the incoming signal to generate a desired outgoing signal that passes through the three-port device to the antenna.

Abstract: An electromagnetic reflector includes an antenna that receives an incoming signal and that transmits an outgoing signal. A three-port device, such as a circulator, has a first port electromagnetically coupled to the antenna. An RF circuit has an input that is electromagnetically coupled to the second port of the three-port device and an output that is electromagnetically coupled to the third port of the three-port device. The RF circuit changes at least one of a gain and a phase of the incoming signal to generate a desired outgoing signal that passes through the three-port device to the antenna.

Abstract: A signal interface includes a dual-drive device having a first and a second input port that receive an outgoing signal. One of the first and the second input ports also receive an incoming signal. The dual-drive device passes the incoming signal to an output port while isolating the outgoing signal from the incoming signal.

Abstract: A signal interface comprises a non-reciprocal device having a first port that accepts a first electrical signal and a second port that accepts a second electrical signal. The non-reciprocal device passes the second electrical signal through the first port without a phase shift and passes the first electrical signal through the second port with a 180 degrees phase shift. An optical modulator receives an optical signal at an optical input port, a second signal at a first and a second electrical input port, the first electrical signal at a third electrical input port, and the phase-shifted first electrical signal from the non-reciprocal device at a fourth electrical input port. The optical modulator transmits the second electrical signal to the first port of the non-reciprocal device without a phase shift and modulates the first electrical signal on the optical signal and providing the modulated optical signal at an optical output port of the optical modulator.

Abstract: A method of forming optical quality surfaces in optical material is described. In particular, high optical quality end face surfaces are provided in diffused channel waveguides formed on LiNbO.sub.3 crystal material, or the like. A T-shaped trench is first formed by laser ablation. The top of the "T" bisects a plane orthogonal to and passing through the waveguide. The lower part of the "T" is centered on the longitudinal axis of the waveguide and retains an optical fiber abutting the end face.A diamond polishing wheel is inserted in the top trench to polish the end face prior to affixing the fiber optic.

Abstract: An I-V curve tracer measures an I-V relationship of an electrical device during transient conditions. In operation, the curve tracer couples across the device a fixed-value inductive or capacitive load. While the current and voltage flowing through the device approach steady-state levels, the voltage and current are sampled and stored in a memory upon predetermined incremental changes in one parameter of the device such as voltage. A digital representation of one parameter, such as voltage, constitutes a memory address and another parameter, such as current, is stored at that address in the memory. A data processor subsequently retrieves the memory data and addresses to display or plot the I-V relationship of the device. This parametric sampling technique assures that the measurements are coincident in occurrence with the sweeping of the I-V curve and eliminates the need for complex control and timing circuits.

Abstract: A photovoltaic-thermal solar cell including a semiconductor body having antireflective top and bottom surfaces and coated on each said surface with a patterned electrode covering less than 10% of the surface area. A thermal-absorbing surface is spaced apart from the bottom surface of the semiconductor and a heat-exchange fluid is passed between the bottom surface and the heat-absorbing surface.