CATV Modulator Return Loss Effects On Headend Combining Isolation

Ron D. Katznelson, Broadband Innovations, Inc.

Abstract

This note addresses the impact of broadband return loss of frequency agile modulators when combined through headend combining networks. In particular, the effect of less-than-ideal output return loss values are examined and it is shown that even under the worst case conditions, a broadband return loss of 10 dB produces only small reductions in isolation that still permit cable operators to meet their headend combining specifications.