Co-Design of Phase Shifters and Antenna Elements For Series-Fed Arrays with Improved Performance (Invited)

In this talk, we present the co-design of phase shifters and antenna elements for series-fed arrays (SFA) to improve the performance, including the wider return loss bandwidth, lower sidelobe level (SLL), smaller gain variation, and larger achievable radiation range. We find the return loss and current distribution bandwidths of series-fed network (SFN) in SFA are dominated by its the input reactance slope. The ratio of phase shifter’s impedance Z 0 and antenna element’s impedance Z L plays an important role in it. When the optimal Z 0 /Z L makes the input reactance slope equal to zero at the center frequency, the bandwidth of SFN can be highly extended by 2~4 times compared with non-optimal solutions. Herein, four classical types of SFNs are investigated and synthesized. The closed-form optimal formulas for these SFNs are further deduced under the specified element number N and current distributions I 1 , I 2 , … and I N . By virtue of the proposed co-design method, the designed SFA exhibits enhanced impedance and radiation bandwidths as predicted.