A Nonuniform Compressed High-Order Mode Dipole With Sidelobe Suppression

A nonuniform compressed high-order mode dipole with suppressed sidelobe is proposed and investigated. The main performance characteristics, such as directivity, sidelobe, and radiation resistance of a third-order mode dipole with two independent compression coefficients are fully investigated. The investigation shows that enhanced directivity, suppressed sidelobe, and high radiation resistance are achieved simultaneously by selecting the appropriate compression coefficients. The compressed converse current leads to the sidelobe suppression. To verify the investigation, a third-order mode dipole antenna with nonuniform compression is designed, fabricated, and measured. The measurement shows that the reflection coefficient is less than −10 dB over the band of 2.46–2.65 GHz (one of the sub-6 GHz bands of fifth generation). The achieved gain is 4.7 dBi. The sidelobe level is less than −15.4 dB, 9.4 dB lower than the uniform compressed third-order mode dipoles.