Design of a Rotman lens antenna array for wide-scan and beam uniformity applications

Rotman lens, which have the advantage of broadband and simple design, is one of the most popular multi-beam feed network. Nevertheless, its insertion loss and power uniformity received by array ports worsen with the increasing of incidence angle. In this paper, we design a wide-scan and low loss insertion Rotman lens based on substrate integrated waveguide (SIW). At the center operating frequency 2.4 GHz, the insertion loss is less than 2.5 dB within the ±40° scanning area and is less than 3.4 dB within the ±50
^°
scanning area. After that, the amplitude and phase information outputted by the Rotman lens are fed into the 4×12 patch antenna array. The simulation result has indicated that the beam gain differences within ±50° scanning area are less than 0.9 dB. Hence, this beam uniformity design suit for satellite communications.