Sidelobe Suppression of Dual-Mode Compressed High-Order-Mode Dipole by Loading Bent Stubs

A dual-mode compressed high-order-mode dipole loaded with bent stubs is presented for sidelobe suppression. When the high-order modes are introduced to achieve high gain, the sidelobes are generated due to the reverse currents along the dipole. To suppress the sidelobes, the bent stubs are used to impair the reverse currents. By bending the stubs, the sidelobe level (SLL) is decreased by 12 dB, on average. A prototype is fabricated and measured to validate the principles. The measurements show that the gains are higher than 4.4 dBi over the entire operating band of 3.26–4.075 GHz (22.2%). Within the desired
n
78-band (3.3–3.8 GHz), the measured radiation patterns are consistent with simulations, and the suppressed SLL is less than −10 dB.