Design of a phased array with the lower mutual coupling for the satellite application

Design of a phased array antenna with lower mutual coupling for the satellite application operating in Ku band is introduced in this paper. By loading the metal cavity around the array element, the mutual coupling effect can be reduced and then improve the scanning performance of the phased array antenna. With this method, the characteristics of phased array antenna with ±60° scanning in two dimensions are analyzed. To verify this design, 5×5 subarray and 16×16 array are studied. The measured results show that the mutual coupling between the elements is less than-16dB. The array element has an impedance bandwidth (VSWR≤2) of 11% (15.1—16.8 GHz). In addition, within the bandwidth of f₀±500 MHz, the E-plane of the radiation pattern has a 3dB beam-width of more than 113° and a 5 dB beam-width of more than 122°, while the H-plane has a 3 dB beam-width of more than 98° and a 5 dB beam-width of more than 113°. Based on the simulation, a prototype of the 5×5 array antenna is fabricated herein. The measured results agree well with the simulated ones, which proves the effectiveness of the design. The beam width of the proposed element fully meets the requirement of a phased array antenna with a ±60° scanning range and can be used in phased radar system.