一种辐射零点可控的紧凑型滤波贴片天线

提出了一种辐射零点可控的紧凑型滤波贴片天线。该滤波天线以基本的微带贴片天线为原型，主要由一个简单的金属辐射贴片和两个对称的分割形槽组成。两个分割形槽蚀刻在金属贴片上，使得高/低频段分别产生两个宽边辐射零点，从而引入滤波选频功能。该结构未引入额外滤波电路和其他寄生单元，节省了空间尺寸，结构更加紧凑；两个辐射零点独立可控，提高了设计的灵活度。且在实现滤波选频功能的同时，对天线增益的影响很小。利用HFSS仿真软件优化滤波天线结构，制作了一个实物模型并进行了测试。测试结果与仿真结果基本一致。测试结果表明，提出的滤波天线工作在2.40 GHz，两个独立可控的辐射零点分别位于1.96 GHz和2.66 GHz，平均实际增益约为7.0 dBi，带外抑制水平超过39 dB。

A compact filtering patch antenna with independent controllable radiation nulls

This paper presents a compact filtering patch antenna with independent controllable radiation nulls. The antenna is principally composed of a simple radiation patch antenna and two split-shaped slots. Taking the basic microstrip patch antenna as the prototype, the filtering and frequency selection function is generated by adding the segmenting slot. Two broadside radiation nulls are generated by two slots in the upper/lower band respectively. According to the circuit structure, HFSS simulation software is used to optimize the structure and adjust the feeding position, and the filtering function is obtained. Without using additional filtering circuits, this design method saves space size and reduces the loss of antenna gain. For demonstration, a prototype is fabricated and tested. The simulation results agree well with the measured ones: the proposed microstrip patch filter antenna operates at 2.40 GHz; there are two radiation nulls at 1.96 and 2.66 GHz at two band-edges of the boresight gain response for improving skirt selectivity; at the same time, the frequency of the two radiation nulls can be controlled independently by controlling the length of the two split slots, increasing the flexibility of the design; the average realized gain of this filtering antenna is about 7.0 dBi and the out-of-band suppression level is more than 39 dB.