Series-Fed Omnidirectional mm-Wave Dipole Array

A compact series-fed, omnidirectional printed dipole array for millimeter-wave (mm-wave) bands n257, n259, and n261 is proposed. A series feed technique with microstrip to grounded-co-planar waveguide (CPW) transition was used to feed the antenna. The prototype was fabricated and measured for the range from 27.25 to 28.5 GHz. The measured peak gain is 10.3 dBi with a maximum azimuthal ripple of 4.4 dB.