Alcatel

Alcatel N.v.

Klaus Braun

Werner Berger

Rolf Heidemann

Ulrich Steigenberger

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

An optical receiver receives a wideband input signal and separates the wideband input signal into at least a first narrowband signal (FB.sub.1) and a second broadband signal (FB.sub.2). A photodiode (3) receives the wideband input signal and generates a photo-current responsive to the wideband input signal. The photodiode has a first terminal (K) and a second terminal (A). First (1) and second (2) subcircuits respectively are coupled to receive the photo-current generated by the photodiode (3). The first subcircuit (1) includes an amplifier. The first narrowband signal (FB.sub.1) and the second broadband signal (FB.sub.2) are respectively separated from the wideband input signal with the first subcircuit (1) and the second subcircuit (2). The narrowband signal (FB.sub.1) includes a digital (telephone) signal and the broadband signal (FB.sub.2) includes a CATV signal which are both included in the wideband input signal.

Optical receiver with signal splitter

A circuit arrangement includes a signal source having a high-ohmic complex output impedance, an amplifier having a low-ohmic input impedance for receiving a signal from the signal source, and a tuned quarter wavelength circuit for matching the signal source to the amplifier.

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Stuttgart, Germany

Klaus Braun