Comparison of efficient small antennas for wireless microsensors through simulation and experiment

This work presents the results of a study on a set of small antennas for wireless microsensor devices. We consider antennas that are small compared to the wavelength, and can be fitted on a small PCB. The key point regarding small antennas is that their performance is heavily dependent on their electrical size. The product of the bandwidth and the gain is a function of the size of the antenna, so that the gain can only be increased at the expense of bandwidth, and vice versa. Our goal was not only to miniaturize the elements, but to maintain acceptable radiation characteristics as well. A reasonable figure of merit is suggested, in an attempt to gather all fundamental antenna parameters in a single quantity. The behavior of the examined schemes was characterized through simulation and experimental validation.