A slot-unipole energy-density mobile antenna

Radio signals received by moving vehicles in mountainous regions or in cities with high buildings may exhibit violent amplitude fluctuations because of the existence of standing-wave patterns. An energy-density antenna which samples the electromagnetic energy density has been suggested as a means for combatting this spatial fading phenomenon. A unipole and crossed slots combination with suitable circuitry serves as a novel and convenient energy-density antenna. Using a simple reflecting-plane model, the range of amplitude variation of the receiver output as a function of signal direction is examined.