Bounds of Uncertain Interference Between Closely Located Antennas

The uncertainty in the characteristics of two antennas located close together and operating at different frequencies is considered. The formulations of antenna performance indexes on one antenna by admittance parameters are obtained with respect to the load impedance at the feed point of the other antenna. All the antenna performance indexes obtained here are expressed as the ratio of quadratic functions of the load impedance, and exact formulas are derived for the quick calculation of their bounds with respect to the load impedance which is uncertain and changes with frequency.