Abstract: In one embodiment, a system is configured to generate a time reference where the system includes a bi-directional loop configured to have a first propagation speed in a first direction and a second propagation speed in a second direction, wherein the first propagation speed is substantially equal to the second propagation speed. In one embodiment, the system further includes a plurality of system elements coupled to the bi-directional loop, wherein each respective system element of the plurality of system elements is configured to determine a time reference common to each as an average arrival time at the respective system element of a first signal transmitted in the first direction over the bi-directional loop and a second signal transmitted in the second direction over the bi-directional loop.

Abstract: A waveform generation and measurement module that may be used in automated test equipment. The waveform generation and measurement module includes high speed SERDES (or other shift registers) that are used to digitally draw a test waveform. Additional high speed SERDES may also be used to receive (in serial form) a response waveform from a device under test and convert it to parallel data for high speed processing. The waveform generation and measurement module may be implemented in field programmable gate array logic.

Abstract: In one embodiment, a system is configured to generate a time reference where the system includes a bi-directional loop configured to have a first propagation speed in a first direction and a second propagation speed in a second direction, wherein the first propagation speed is substantially equal to the second propagation speed. In one embodiment, the system further includes a plurality of system elements coupled to the bi-directional loop, wherein each respective system element of the plurality of system elements is configured to determine a time reference common to each as an average arrival time at the respective system element of a first signal transmitted in the first direction over the bi-directional loop and a second signal transmitted in the second direction over the bi-directional loop.

Abstract: A power amplifier to provide a compensated output voltage to a load through a series-connected impedance. The power amplifier includes an inner positive current feedback loop that is capable of sensing changes in the resistance of the load, and which adjusts the effective impedance of the series-connected impedance seen by the load to reduce current induced changes in the level of the compensated output voltage provided to the load due to the presence of the series connected impedance.

Abstract: A method and apparatus for shielding and/or redirecting radiation from a portable communication device, such as a cellular telephone is provided. In one embodiment, a conductive shield or passive antenna is positioned between the cellular telephone active antenna and the location of the user's head when the cellular telephone is in the operative position. In one embodiment, the shield is configured to reflect radiation in a pattern which is multi-directional. In another configuration, the shield is configured to reflect radiation in a preferred axial direction. Latches or other devices can be used to assure that the shield is positioned and maintained in the desired location. Insulation may be used between the shield and antenna. The shield can be made of a single unitary piece or a plurality of disconnected pieces. The shield may be reconfigurable, e.g., to accommodate a telescoping antenna.