Isolation enhancement and size reduction of printed-antenna pairs for broadband microwave-photonic access-point

The introduction of new wireless access technologies in the crowded spectrum requires wireless infrastructures and user equipments to provide multiband and multiservice capabilities. One approach to cope with this challenge is to design a broadband microwave-photonic access-point that covers all required bands. This paper investigates isolation enhancement of miniaturized antenna-pair used in the broadband system. Among available isolation enhancement techniques, defected-ground (or ground-slot) and ground-stub are chosen due to their wideband feature. The simulations and measurements conducted to printed monopole antenna pairs show that the chosen techniques are effective in improving isolation between uplink and downlink antenna pair.