Alcatel

Alcatel Sel Aktiengesellschaft

Fuba Communications Systems Gmbh

Werner Berger

Klaus Braun

Gert Van Der Plas

Christiaan H Sierens

Ulrich Steigenberger

Bernhard Stascheit

Stephen Harnisch

Friedemann Weiss

Denis J Mestdeagh

A rack, in particular for cable television, having a number of modules whose inputs and outputs are connected by means of cables for the transmission of radio frequency signals and control signals, is described. The modules () are connected via the common inputs and outputs by means of coaxial cables () which carry radio frequency signals as well as coded control signals.

Electronic equipment rack having cables carrying both radio frequency and coded control signals

A diode network having at least one diode which during operation is located in the path of an HF signal, a predetermined diode voltage being applied to the diode to adjust its operating point, is characterised in that a control device is provided to maintain the diode voltage constant. With the invention it is advantageous that, due to the measurement of the DC voltage acting on the diode itself and influencing the operating point, it is not necessary to provide a low-resistance coupling between a voltage source and the diode, with respect to direct current.

Operating point adjustment for a diode of a diode network by means of voltage injection

A circuit to reduce the temperature-dependence of a predistorter diode in a predistorter for an external optical modulator characterized in that a predistorter diode (D,, D,) is connected in series with an ohmic resistance (Rv) and the series circuit is fed from a power supply in operation, whereby the voltage V,of the power supply and the ohmic resistance are selected such that when the temperature of the predistorter changes the curvature of the temperature-dependent current-voltage curve for the predistorter diode hardly varies at the respective operating point. One advantage of the invention is the very simply type of compensation that it allows.

Temperature stabilization of a predistorter

Temperature stabilization of a predistorter with voltage supply

The compensation device is used in an optical network where signals are transmitted from a main station (M) to one or a plurality of user stations (US1 to US3). It compensates for analog optical signal distortion caused by laser chirp of a laser in the main station (M) which generates said analogue optical signal and fiber dispersion of the fiber link over which the optical signal is transmitted. The device includes a distance measuring device (R) generating a result signal (MS) indicative of the distance between the main station and the user stations and which is possibly already available in the network to perform ranging when the latter network is also used to transmit digital signals from the user stations to the main station using Time Division Multiple Access. It also includes a processing circuit (PC) which in response to a given laser chirp and the result signal, provides a tuning signal (V) to tune the bias voltage of a varactor diode (VD) which is part of the compensation circuit inserted in the electrical signal path. In an optimal implementation the measuring device (R) and the processing circuit (PC) are located in the main station (M), while the varactor diode (VD) is located in each user station.

Compensation device

Growing community of inventors

Ditzingen, Germany

Werner Berger