This study presents a compact wide stopband microstrip diplexer which is designed based on a novel resonator structure. This novel resonator consists of a main hairpin cell loaded by a smaller hairpin and T-shaped cells. The presented diplexer operates at 3.46 and 4.75 GHz for IEEE 802.16 worldwide interoperability for microwave access (WiMAX) and IEEE802.11a Wireless LAN applications, respectively. The main advantages of the proposed diplexer are its flat channels, two wide bandwidths, attenuated harmonics, low insertion losses better than 0.18 dB, several transmission zeros and sharp frequency response. From first up to fifth harmonics of the proposed diplexer are well attenuated with the maximum harmonic level −20 dB. Meanwhile, the simulation results show that the presented design can suppress harmonics up to 44 GHz. In other words, the harmonics from the 1st up to 12th are suppressed. The group delay at both channels is lower than 1.1 ns, which is good for a microstrip diplexer. This good performance is obtained, while the overall area of the designed diplexer is only 0.037 . Based on the comparison results, the proposed diplexer has a compact size, the minimum group delay and a wide stopband rejection. The proposed diplexer is fabricated and measured. Both simulation and measurement results are in good agreement.

中文翻译：

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紧凑的宽带阻带微带双工器，带有扁平通道，用于WiMAX和无线应用

这项研究提出了一种紧凑的宽带阻带微带双工器，它是基于一种新颖的谐振器结构设计的。这种新颖的谐振器由一个较小的发夹和一个T形单元组成的主发夹单元组成。对于微波接入（WiMAX）和IEEE802.11a无线局域网应用的IEEE 802.16全球互操作性，本双工器的工作频率分别为3.46 GHz和4.75 GHz。拟议的双工器的主要优点是其平坦的信道，两个宽带宽，衰减的谐波，优于0.18 dB的低插入损耗，多个传输零点和清晰的频率响应。所提出的双工器的从第一到第五谐波都被很好地衰减，最大谐波电平为-20 dB。同时，仿真结果表明，该设计可以抑制高达44 GHz的谐波。换一种说法，从1到12的谐波被抑制。两个通道的群时延均低于1.1 ns，这对于微带双工器非常有用。获得了良好的性能，而设计的双工器的总面积仅为0.037 。根据比较结果，提出的双工器具有紧凑的尺寸，最小的群时延和宽阻带抑制比。拟议的双工器已制造并测量。仿真结果和测量结果吻合良好。