This paper presents a compact dual-band filtering antenna without extra employing of filter structures. The antenna is designed using a planar dual-composite right/left-handed (D-CRLH) transmission line unit cell, where the filtering function is achieved through current cancellation between the D-CRLH resonators. The antenna is designed to function at 3.0 and 5.1 GHz, which can serve different WLAN applications. The antenna is a co-planar waveguide fed with a very compact size of only 30 × 16 mm2. Compared to the conventional patch antenna, the antenna size is only 17% at 3.0 GHz and 31% at 5.1 GHz. Despite the small size, the antenna preserves a good omni-directional radiation pattern at the two resonant frequencies with a measured realized gain of 2 and 2.7 dB, respectively. At the stopband in-between the two resonant bands, the reflection coefficient is almost 0 dB at 4.25 GHz and complete non-radiation is proved with a −11 dB measured realized gain. The different antenna filtering functions are verified by full-wave simulation and measurements.

本文提出了一种无需额外使用滤波器结构的紧凑型双频滤波天线。该天线采用平面双复合右/左手 (D-CRLH) 传输线单位单元设计，其中滤波功能通过 D-CRLH 谐振器之间的电流抵消来实现。该天线设计为在 3.0 和 5.1 GHz 下工作，可服务于不同的 WLAN 应用。天线是一个共面波导馈电，尺寸非常紧凑，仅为 30 × 16 mm 2. 与传统贴片天线相比，天线尺寸在 3.0 GHz 时仅为 17%，在 5.1 GHz 时为 31%。尽管尺寸很小，但天线在两个谐振频率上保持良好的全向辐射方向图，实测增益分别为 2 和 2.7 dB。在两个谐振频带之间的阻带处，反射系数在 4.25 GHz 时几乎为 0 dB，并且通过 -11 dB 的实测实现增益证明了完全无辐射。通过全波仿真和测量验证了不同的天线滤波功能。