Bandwidth potential and electromagnetic isolation: tools for analysing the impedance behaviour of antenna systems

Abstract:
Three approaches to analysing the impedance characteristics of antennas and antenna systems are discussed. The concept of bandwidth potential computes the obtainable bandwidth of an antenna through automatically generated two-component matching circuits at all frequencies. The original concept of bandwidth potential that matches the impedances to 50 Ohm is generalised to include optimisation of the matching circuit to maximise the obtainable bandwidth. The second approach uses power waves to simplify the analysis of matching circuits. As opposed to travelling waves, the power waves describe the propagation of power in microwave networks directly. In the third concept both ports of a two-port antenna system are sequentially matched for each frequency and the resulting isolation is called the electromagnetic isolation that is independent of antenna matching.