Efficient Design of Tightly Coupled Dipole Array Using an Equivalent Circuit-Based Approach

This paper proposes an efficient and systematic design approach for tightly coupled dipole array (TCDA) designs. In this approach, the radiator structure and feeding structure are designed and optimized based on their equivalent circuit models (ECM) respectively. A novel ECM is proposed to accurately describe the impedance characteristics of the radiator structure with dual-diamond dipoles. The proposed ECM of the radiator structure keeps its accuracy for variable design parameters. The ECM of the proposed feeding structure is also developed to analyze its impedance characteristics. As compared with conventional brute-force optimizations based on full-wave simulations, the two ECMs make it easy and efficient to design wideband TCDAs. A dual-polarized TCDA is designed with the proposed approach to illustrate the efficiency of the approach. The resultant TCDA operates in a wide frequency band of 0.87-10.14 GHz with VSWR <= 2 for broadside radiation. Meanwhile, the VSWR value under all conditions (broadside, +/- 60 degrees scanning in E- and H-planes) remains <= 3 over the frequency band of 0.8-9 GHz. A 10 x 10 prototype is fabricated to demonstrate the design.