Ke Kommunikations Elektronik

Ke Kommunikations-elektronik Gmbh & Co.

Andreas Hennig

Martin Brahms

Andreas Timmermann

A circuit arrangement is indicated to generate a clock frequency for a data transmission system by using a voltage-controlled fundamental wave quartz oscillator (VCXO), whose frequency can be changed within narrow limits as a function of the control voltage. To double the frequency of the fundamental wave quartz oscillator (VCXO), its output (A) is connected to the input of a rectifier bridge circuit (1) having an ohmic resistance (2) placed at its output. The ohmic resistance (2) is connected to both inputs of a comparator (3), and the clock frequency (f) is present at the output of the comparator.

Circuit arrangement to double the clock frequency for a data

A controllable amplifier, which has two symmetrical outputs, at which two output signals mirror-symmetrical with respect to each other are present, is used for amplification of a burst signal. To achieve the largest possible eye opening of the signals to be fed to a comparator, a predetermined d.c. voltage difference for the formation of matched signals is adjusted for both output signals. After this, the arithmetic mean values of the two matched signals are formed and are fed to a second comparator. The output value of the second comparator is fed to an integrator, to which a reference voltage is also fed. In case of a deviation of the mean values of the two matched signals from each other, the amplifier is adjusted in a compensating direction by the integrator.

Procedure and apparatus for amplification of a burst signal

For controlling the level of electrical signals a circuit arrangement is formed with two series connected amplifiers. A first amplifier containing a first variable resistor, operates at maximum amplification when a low input signal level is received. A second amplifier comprises a series connection of a second variable resistor and a current-controlled voltage source with two complementary outputs. The outputs of the voltage source are connected to a comparator and a controller with two separate outputs. One of the controller outputs transmits a control signal while the other output simultaneously transmits a blocking signal. A first output of the controller is connected with the first variable resistor, while a second output of the controller is connected to the second variable resistor.

Growing community of inventors

Garbsen, Germany

Andreas Hennig