A broadband filtering quasi‐YAGI antenna with wide stopband

Abstract

AbstractThis article presents a novel filtering quasi‐Yagi antenna with ultra‐wide passband and ultra‐wide stopband. By employing an antipodal connection between the dipole arms and the feedline, the profitable modes of the dipole can be excited and controlled to produce a wide operating band. Without increasing the antenna size, the elaborately arranged parasitic elements and the band‐stop element can realize the filter‐like response with sharp roll‐off rates and high out‐of‐band suppression levels. Measured results show that passband and stopband can be improved to 2.65–6.05 GHz (78.2%) and 6.3–13.3 GHz (up to 3.1 f0, f0 is the center frequency of the antenna), respectively. Radiations keep stable across the passband. The measured in‐band average gain is ∼ 4.4 dBi, whereas the out‐of‐band radiation suppression is more than 20.2 dB.