P/spl times/M antennas for immunity testing and other field generation applications

Field strength and frequency range requirements for contemporary immunity testing standards combined with amplifier limitations impose severe difficulties for compact antenna designs. Current approaches generally involve broadband dipole antennas sometimes combined with log-periodic dipole arrays. Certain combinations of electric and magnetic dipole radiators known as P/spl times/M antennas offer definite advantages over the broadband dipole antennas currently in use: bandwidth, gain, front-to-back ratio, radiation efficiency, power handling ability, and, to a lesser degree, uniform field area. These advantages are quantified and practical implementation of a P/spl times/M antenna is discussed. Nearfield gain and ground plane interaction are also discussed. Finally, a prototype antenna is numerically modeled and experimentally characterized.