Applied Optoelectronics, Inc.

Steven Blashewski

Rafael Celedon

Mark Siejka

David Stewart

Stéphane Chapeau

A forward and reverse test point circuit with a switchable termination may be used to provide testing of forward and reverse RF signals in an RF amplifier before and/or after amplification. The switchable forward and reverse test point circuit includes at least one switchable termination circuit coupled between forward and reverse terminals of a directional coupler and at least one test point. During forward signal testing, the forward terminal is switched to the at least one test point and the reverse terminal is switched to a termination. During reverse signal testing, the reverse terminal is switched to the at least one test point and the forward terminal is switched to a termination. The RF amplifier including the switchable forward and reverse test point circuit may be used in a hybrid fiber-coaxial (HFC) network delivering CATV services and may be capable of amplifying RF signals up to 1.8 GHz.

Forward and reverse test point circuit with switchable termination for use in an RF amplifier

Automatic gain control (AGC) may be accomplished in a radio frequency (RF) amplifier in a hybrid fiber-coaxial (HFC) network using a wideband RF tuner to select multiple pilot channels (e.g., frequencies in lower and upper portions of an RF signals spectrum) for use in measuring power and determining a correction to be applied to the RF amplifier. The power of the pilot channel or channels may be measured, for example, using a received signal strength indicator (RSSI) from the wideband RF tuner or using a power detector circuit. Using the wideband RF tuner allows selectable gain and/or tilt control across a wideband spectrum, such as a channel spectrum of a CATV downstream RF signal, to maintain stable RF output levels of the amplifier as RF input levels vary. The RF amplifier may be a line extender amplifier used in a CATV HFC network to amplify a wideband RF spectrum of up to 1.8 GHz.

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Duluth, GA, United States of America

Steven Blashewski