ESPAR antenna is electrically steerble parasitic radiator array antenna where the parasitic radiators are loaded with variable reactance devices. In this report, design criterion of binary reactance diversity that switches the loading reactance values of ESPAR antenna is studied. We analyzed the diversity reception at mobile terminal in multipath environment with simple circuit equations and a steering vector. Simulation result shows 12 dB diversity gain at the bit error rate of 10{sup}(-3) and the branch correlation is almost zero, though the element space is only 0.1 wavelength. We found that the equivalent weight vector, which is normalized current vector of the elements, plays an important part to choose the optimum loading reactance pair as the diversity branches.
展开▼
