Abstract: A dynamic load fixture (DLF) for testing a unit under test (UUT) includes a lateral load system that applies a time-varying lateral load profile to the UUT drive shaft and an encoder that measures its angular rotation. An isolation stage suitably constrains the encoder from rotating about the axis while allowing it to move in other directions in which the application of the lateral force induces motion. The lateral load system includes a load bearing around the drive shaft, an actuator that applies a lateral force to the load bearing, a force sensor for measuring the applied lateral force, and a lateral controller for adjusting a command signal to the actuator to implement a lateral load profile. The DLF may also include a torsion load system that applies a time-varying torsion load profile to the drive shaft.

Abstract: A general purpose system and method for transmitting and coherently detecting UWB waveforms is predicated on the formation of conjugate pair of UWB waveforms. The in-phase and conjugate quadrature waveforms are orthogonal to each other and have the same power spectrum so that when squared and added they sum to the modulation envelope of the waveforms. By defining the waveform pair in this manner, a relatively simple and inexpensive transceiver can be used to transmit and receive the waveforms and yet preserve maximum range resolution and recover all possible energy in the returned waveforms. The transceiver transmits the in-phase UWB waveform and the conjugate quadrature UWB waveform with either a known time delay or orthogonal polarization relation. The time delay may be varied to suppress aliased return signals.

Abstract: An optical sensor system (20) has an optical detector (28) with an active detector area (38) and a detector output signal (40). A test-signal optical source (44) has a controllable optical source (48) having an output of a wavelength detectable by the optical detector (28), and a test-signal director (50) that directs the output of the optical source (48) to the active detector area (38) of the optical detector (28). A housing (22) encloses the optical detector (28) and the test-signal optical source (44). A test instrumentation controller (52) controls the operation of the optical source (48), and receives the detector output signal (40) for evaluation.

Abstract: Although THz radiation is naturally emitted by hot objects, the intensity levels are too weak to be considered as a practical THz source for most applications. Photonic crystal structures are used to modify the thermal emission peak associated with the standard Planck blackbody spectral distribution so that the THz region is dramatically enhanced. The photonic crystal core is preferably combined with variable Q defect cavities and a wave guiding and power combining structure so that the radiated THz energy is efficiently collected and directed to an output antenna. Higher THz emissions are realized by embedding a finer (higher frequency) photonic crystal structure within a coarser (lower frequency) structure.