A CPW-Fed Printed Loop Antenna for Ultra-Wideband Applications, and its Linear-Array Performance

A small CPW-fed loop antenna is described. The single antenna has a measured relative impedance bandwidth of 70%. Radiation patterns show stable co-polar and low cross-polar characteristics within the specified bandwidth. The small size of the radiator (0.5λ at 13.6 GHz) makes it suitable for being used in linear-array applications. The linear-array performance of the antenna is investigated by means of simulations and measurements. The mutual coupling in the array environment is reduced by means of slots placed on the antenna's surface. The impedance bandwidth is almost preserved after the antennas are embedded in an array environment. The radiation patterns of the array is also investigated by means of simulations and measurements.