A Printed Wideband Squintless Traveling-Wave Antenna

In this letter, a printed wideband squintless traveling-wave antenna is proposed. The antenna is composed of a transmission line, which is loaded with a set of bent branches that are connected to radiators. With branches of different lengths, the main beam can be designed in an arbitrary direction between the backfire and the endfire. Compared with previously published squintless linear array antennas, the proposed antenna owns a novel arrangement of branches, which is compact especially when there are a large number of radiators. The working principle is explained and a prototype of a 16-branch antenna is fabricated for validation. The measurement results show that the direction of the main beam is fixed at 30° ± 2° (measured from the broadside direction) in the range of 9.0–14.0 GHz (with a radiation bandwidth of 43.5%) and the peak gain is 11.0 dBi.