Feeding structure influence on side lobe suppression of printed antenna array with parallel reflector

The paper investigates the feeding structures for printed antenna arrays with parallel reflector and their influences on antenna parameters. Two printed antenna arrays are presented. The first consists of ten series fed symmetrical dipoles with tapered impedances. The second is the array of eight symmetrical dipoles that are fed by a tapered distribution. The feeding structures for both antennas are realized in symmetrical (balanced) microstrip technique eliminating surface wave effect. However, a parasitic radiation from a feeding network cannot be avoided and it affects antenna performances, especially side lobe suppression. This influence is the most obvious for the antenna with parallel reflector where there is not isolation between array and feeding structure.