A Balanced Filtering Quasi-Yagi Antenna With Low Cross-Polarization Levels and High Common-Mode Suppression

Abstract

A balanced planar quasi-Yagi antenna integrated with a bandpass filtering response is presented in this paper. The proposed balanced antenna consists of a balanced stepped-impedance microstrip-slotline transition structure, a driver dipole, a parasitic strip, and a bandpass filtering unit. A good differentialmode (DM) passband selectivity is formed by inserting a microstrip stub-loaded resonator (SLR) in the feed line of the quasi-Yagi antenna. This integration enables the antenna to achieve both compact size and high frequency selectivity. By controlling the dimensions of SLR, the central frequency and fractional bandwidth (FBW) can be easy to be adjusted. Meanwhile, the microstrip-slotline transition structure can achieve a good wideband common-mode (CM) suppression without affecting the DM ones, thus simplify the design procedure. The proposed antenna with low cross-polarization level and high CM rejection is found to be comparable to the conventional quasi-Yagi antenna. Furthermore, there are two radiation nulls on both sides of the passband to improve the selectivity effectively. In order to validate its practicability, the balanced antenna is designed and fabricated. The experimental results exhibit that the designed balanced filtering antenna features good filtering response, low cross-polarization level, and high CM rejection.INDEX TERMS Balanced antenna, filtering antenna, CM suppression, low cross-polarization.

A high selectivity planar filtering quasi‐Yagi antenna

“…Recent years, novel quasi-Yagi antennas are proposed to achieve filtering gain response. [8][9][10][11][12] In Shi et al, 8 by inserting a double-sided parallel-strip line (DSPSL) filter between the driven dipole and the reflector, a quasi-Yagi antenna with 5.5% bandwidth and flat gain response is achieved. In Zang et al, 10 a Yagi-Uda filtering antenna is proposed by embedding a microstrip bandpass filter (BPF) in a planar Yagi-Uda antenna.…”

“…Recent years, novel quasi‐Yagi antennas are proposed to achieve filtering gain response 8–12 . In Shi et al, 8 by inserting a double‐sided parallel‐strip line (DSPSL) filter between the driven dipole and the reflector, a quasi‐Yagi antenna with 5.5% bandwidth and flat gain response is achieved.…”

A broadband and low cross‐polarization balanced dual‐polarized cross quasi‐yagi antenna

“…Nevertheless, an extra balun is required for the single‐ended antennas to be connected with the balanced systems, which will result in additional complex structure, expensive cost, and large losses for the microwave front‐ended circuits. Furthermore, the differential antenna can achieve low cross‐polarization levels 5‐7 . Therefore, the balanced dual polarized antennas are more suitable for the balanced systems.…”

A broadband filtering quasi‐YAGI antenna with wide stopband

“…On the other hand, the quasi‐Yagi antenna has been widely used in the point‐to‐point communication owing to the advantages, such as low profile, easy integration, and high gain. Yet, Yagi antennas generally have a narrow operating bandwidth that hardly meets the broadband applications 12‐14 . Therefore, most of the research on the quasi‐Yagi antenna has focused on bandwidth expansion.…”