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In this paper, a broadband dipole antenna with filtering function is proposed. The proposed antenna as a whole comprises a reflector, coaxial cables, a main radiator, and a cross‐center structure. First, two orthogonal dipoles are used as the main radiator and form dual‐polarization. By adding Y‐shaped branches and a cross‐center structure, the base station antenna realizes the filtering function and expands bandwidth. The antenna has filtering function on both sides of the operating frequency band, and the out‐of‐band radiation suppression can be 16 dB at the upper band. The radiation null can be controlled independently by the additional structure. And the parasitic structure has little effect on the realized gain in the operating frequency band. The measurement results show that the relative operating bandwidth of the proposed antenna exceeds 54%, and the isolation between ports is greater than 27 dB. In the operating frequency band, the realized gain is relatively flat, and the HPBW is in the range of 67.3° ± 2.6°. [ABSTRACT FROM AUTHOR]

A novel umbrella‐shaped wideband circular polarization (CP) antenna with a wide half‐power beamwidth (HPBW) and a wide axial ratio (AR) bandwidth is proposed in this article. Two pairs of symmetrical patch dipoles are attached to the surface of an umbrella‐shaped substrate to broaden both the impedance bandwidth (IBW) and the HPBW. A parasitic metallic ring is located immediately above the umbrella substrate to provide further enhancement of the HPBW. Each patch dipole is excited via a coaxial line, while a conductor balun with length of λ0/4 (where λ0 is the wavelength of the center frequency) is introduced to obtain a feeding balance. Measurement results indicate that the proposed antenna has a −10 dB IBW of 71.3% (from 1.03 to 2.17 GHz), and a 3 dB AR bandwidth of 55.6% (from 1.13 to 2.0 GHz). Additionally, an HPBW of more than 110° is obtained over the whole CP bandwidth, 48.2% of which has an HPBW of more than 120°. The antenna has dimensions of 100 × 100 × 28 mm3, which corresponds to (0.52 × 0.52 × 0.14)λ03. [ABSTRACT FROM AUTHOR]