Abstract: An apparatus for setting an attenuation of an attenuator includes a control transistor, which includes a drain connected to a gate of a shunt transistor of the attenuator. A channel resistance of the shunt transistor corresponds to a current density of the control transistor, and the channel resistance of the shunt transistor determines the attenuation of the attenuator. The current density of the control transistor is based at least in part on a control voltage input to the apparatus.

Abstract: A multiple power mode amplifier provides a low and a high power mode without using switches. This amplifier may be used in RF applications such as mobile telephones. In the low power mode, the power consumption of the amplifier is reduced, which will increase operation time, especially important for battery-operated devices. In one implementation, the amplifier includes a number of impedance matching network units, impedance transformer, and a power stage.

Abstract: An optical waveguide such as an optical fiber extends across a semi-rigid substrate or optical back plane and is made of conformal materials having indices of refraction selected to provide substantially total internal reflection of light transmitted within a core. An optical pin is made of substantially rigid optically transmissive materials. A receptacle in the substrate or optical backplane removably receives and holds the optical pin to allow a beveled terminal end of the pin to penetrate the core of the optical fiber to establish a gap-less interface that provides an optical path between the core and the pin.

Abstract: A pair of directing elements directs a beam of light into a corresponding optical output from a corresponding optical input. Examples of a pair of directing elements include a pair of tilting mirrors and a pair of support devices. Sensors may be positioned adjacent to the optical output, one directing element, and to both directing elements. Each sensor detects an amount of light hitting that sensor and generates a signal representative of the amount of light hitting that sensor. A controller receives the signal from each sensor and generates one or more correction signals. A correction signal causes a corresponding directing element to be adjusted in order to minimize losses in optical signal power.