Broadband and Gain-Enhanced Compressed Higher-Order-Mode Dipoles Using Parasitic Elements and Stubs to Modify Currents

A novel trimode broadband high-gain dipole with mode compression is proposed in this communication: first, by introducing bend stubs to realize the modification of the forward and reverse currents of the fifth- and seventh-order modes, to improve the gain; second, by introducing straight stubs to extend the current path of the seventh-order mode, to shift the seventh-order mode left, and to combine with the fifth-order mode; and finally, by introducing parasitic dipoles to further modify the currents and to generate the coupled resonance modes, to enhance the gain and the bandwidth again. Characteristic mode analysis is utilized, and a prototype is fabricated to verify the principle experimentally. The measurement shows that the antenna worked in the 3.25–4.05-GHz band (25.5%) and a high gain of 7.9 ± 0.6 dBi in the desired n-78 (3.3–3.8 GHz) band.