A method to observe mutual fluctuations between carriers in broadband communication systems

A procedure to observe the mutual fluctuations between two carriers after transmission through a millimeter-wave communication system is proposed and implemented. By monitoring the spectrum of the beat tom of the two carriers after being retrieved from the receiver IF output, the degree of correlation in their phase fluctuations can be assessed. The method has been applied to a Ka-band communication system with over 1 GHz instantaneous bandwidth and found to be effective. Employing standard measurement equipment, this approach to channel characterization can be conducted while the communication link is in service