Abstract: System for adjusting a power level of an optical signal at an input to a component in a network element that forms part of an optical network. The system includes a variable optical attenuator (VOA) for receiving a first optical input signal and producing an attenuated optical output signal. A detector is coupled to the input of the component for detecting a power value of a second optical input signal that is derived from the attenuated optical output signal. A VOA controller (VOAC) includes logic for receiving the power value, via a signaling channel, and generating selected control parameters that are input to a control input of the VOA for accordingly adjusting a VOA attenuation factor to achieve a selected signal power level at the input to the component.

Abstract: A retractable whip antenna incorporating a matching base loading helix for use in mobile communications devices is disclosed. The antenna functions without the use of a matching circuit since selection of the radiating elements provides a constant input impedance to the transceiver circuitry. The resulting antenna provides excellent gain over the PCS frequency band, low SAR values, circuit design flexibility and low cost. In a preferred embodiment, the retractable whip is comprised of a radiating element with an electrical length of 1/2 wavelength and having a first end attached to a conductive spring contact. The base loading helix comprises a radiating helical element with an electrical length of 1/4 wavelength and having a first end connected to a mobile transceiver circuit and a second end comprising a conductive capturing coil. The radiating whip element is constrained within the coil of the helical element and is freely moveable to an extended or a retracted position.