An efficient, electrically-small, 3-D machined-substrate antenna

An efficient, compact, 3-D machined-substrate dipole antenna for narrow-band wireless monitoring is presented herein. The antenna is designed for an operating frequency of 2.4 GHz with a measured 10 dB return loss bandwidth of 2.7%. Ka of the presented design is 0.5 with a measured radiation efficiency of 94% and gain of 2.5 dB. The design compares well with high efficiency, electrically-small antennas that have been described in the open literature.