An electrically-small monopole phased array antenna for wide band applications

An electrically-small, lightweight, and low RCS (radar cross-section) Monopole Array Antenna has been developed for wide band application. The monopoles were printed on a low dielectric constant (epsilon sub gamma = 2.3) substrate and fed by a modified meanderline microstrip feed structure, with quarter-wavelength stubs to improve feed efficiency. The operational frequency is from 0.65 to 2.0 GHz. The physical size of the monopole array measures only 0.125 wavelength in height. The weight is about 0.3 pounds. A four-element subarray was built and tested. Its overall physical size is 2.5 inches in height by 10 inches in length by 24.4 inches in width. The measured gain and pattern data are presented, as well as the low RCS property and many applications of the monopole array.