This letter presents a high-gain filtering antenna with multiple radiation nulls and enhanced frequency selectivity using substrate integrated suspended line (SISL) technology. The presented antenna is composed of driven patches with slots, parasitic units, stubs, and stacked patches. The first radiation null is caused simultaneously at the upper band edge when the stacked patches are introduced to produce a resonance mode. The second radiation null is produced by the slots on the driven patches at the lower band edge. Due to the TM20 mode of the driven patches, the third radiation null is introduced at higher frequency. Owing to the stubs and parasitic units, the fourth radiation null is caused at lower frequency. The above four radiation nulls achieve excellent filtering performance with high selectivity. The measured results indicate the outstanding performance of the filtering antenna. The passband is from 3.28 to 3.79 GHz, perfectly covering the 5G-N78 band. The peak gain reaches 11.14 dBi, and the out-of-band rejection level is 17.8 dB. In addition, this filtering patch antenna is designed based on low-cost substrate FR4.

中文翻译：

---

面向 5G 应用的基于 SISL 的具有增强频率选择性的低成本高增益滤波贴片天线


这封信介绍了一种高增益滤波天线，具有多个辐射零点和使用基板集成悬挂线（SISL）技术增强的频率选择性。所提出的天线由带槽的驱动贴片、寄生单元、短截线和堆叠贴片组成。当引入堆叠贴片以产生谐振模式时，在上带边缘处同时引起第一辐射零点。第二个辐射零点是由较低带边缘处的驱动贴片上的槽产生的。由于驱动贴片的 TM20 模式，在较高频率下引入了第三个辐射零点。由于短截线和寄生单元，第四辐射零点是在较低频率处引起的。上述四个辐射零点实现了高选择性的优异滤波性能。测量结果表明该滤波天线具有优异的性能。通频带为3.28至3.79GHz，完美覆盖5G-N78频段。峰值增益达到11.14 dBi，带外抑制电平为17.8 dB。此外，该滤波贴片天线是基于低成本基板FR4设计的。