基于无线局域网(WLAN)的应用背景，设计并加工了一款用于WLAN的双频滤波器。滤波器的主体部分采用两阶的阶跃阻抗滤波器(SIR)，馈电方式采用0?平行耦合线馈电方式。测试结果跟仿真结果有很好的一致性，滤波器在两谐振频点2.4 GHz和5.2 GHz处的插入损耗为0.85 dB和1.3 dB。在上述平面滤波器的基础上，进一步分析了圆柱共形对SIR结构谐振特性的影响，利用共形器件的仿真与实际加工装配相一致的准确建模方法，设计了一款圆柱共形双频滤波器，其有更好的赋形性能和选择性。该设计可用于共形通信系统中，具有广阔的应用前景。

A dual-band filter designed for Wireless Local Area Networks(WLAN) is introduced and fabricated. Two-order Stepped Impedance Resonator(SIR) and parallel coupled-line are utilized to design it. Experimental results agree well with simulations, thus validating our design. The insertion losses of two resonant frequencies 2.4 GHz and 5.2 GHz, are 0.85 dB and 1.3 dB respectively. Based on this plane filter, a cylindrical conformal filter is designed through analyzing the influence of conformal cylinder on the resonant characteristic of SIR structure and an accurate modeling method which is consistent with the real fabrication is adopted. The insertion loss is a little bit larger, but the conformal performance and the selectivity become better. This conformal filter can be used in conformal communication system with a broad application prospects.