Patent ID: 7379672
Filing Date: 2008-05-27
Classification: H04B

Abstract:
1. A photonic RF distribution system for optically distributing an RF signal, comprising: a first optical source for generating a first optical signal having a first operating frequency; a second optical source for generating a second optical signal having a second operating frequency; an optical coupler coupled to the first optical signal for obtaining a tapped portion of the first optical signal separate from the first optical signal; a modulator operable to impress an RF modulation signal on the tapped portion of the first optical signal such that a modulated signal is generated; a first coupler for combining the modulated signal with a tapped portion of the second optical signal, thereby forming a combined signal having a difference frequency component; a control photodetector, responsive to the combined signal, to generate a tone signal; and an offset locking circuit, responsive to the tone signal, to tune the operating frequency of at least one of the optical sources such that the first optical signal and the second optical signal are frequency locked.