A 2.45-GHz Electrically Small Slot Antenna

A 2.45-GHz electrically small slot antenna (lambda0/35timeslambda0/35, 3.5times3.5 mm2) is disclosed. Miniaturization is achieved through symmetric inductive loading of an electrically small slot section. It is fabricated on a low-loss fused silica wafer through a back-etch of a 5000-Aring golden metal film, which is 31.5% of the skin depth at 2.45 GHz. The measured bandwidth is 106 MHz and the measured gain is -15 dBi. The theoretical Wheeler-Chu-McLean limit for the gain of a lambda0/35timeslambda0/35 electrically small antenna with a similar Q factor is -9.6 dBi.