This study presents a planar dual‐channel bandpass microstrip diplexer based on a novel structure. It has the very compact size of 0.0081 λ _g² (95.7 mm²) fabricated on 0.787 mm dielectric substrate height. Due to the use of close microstrip sections, several coupling capacitors are created. These capacitors can increase the degree of freedom for controlling the diplexer performance while it is optimized easily. Accordingly, the designed diplexer has a high performance in terms of wide fractional bandwidths, attenuated harmonics, flat channels, high return losses and low insertion losses. The wide fractional bandwidths (FBWs%) of 34.3% at the first channel and 38.6% at the second channel make the proposed diplexer appropriate for the broadband applications. The resonance frequencies are located at f₁ = 1.6 GHz for the L‐band and f₂ = 3 GHz for WiMAX applications. The maximum harmonic level is less than −20 dB for the frequencies up to 6.5 GHz (4f₁). The maximum group delays are <1.26 ns at the first passband and 0.56 ns at the second passband. The proposed diplexer is fabricated and measured for verification. The comparison shows that both measured and simulated results are in a reasonable agreement.

中文翻译：

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一种非常紧凑的微带双工器制造，具有出色的性能，适用于宽带无线应用

这项研究提出了一种基于新型结构的平面双通道带通微带双工器。它具有0.0081的非常紧凑的尺寸λ_克²（95.7毫米² ）制成0.787毫米的绝缘基板高度。由于使用了封闭的微带部分，因此创建了多个耦合电容器。这些电容器可以提高控制双工器性能的自由度，同时易于优化。因此，所设计的双工器在宽的分数带宽，衰减的谐波，平坦的通道，高的回波损耗和低的插入损耗方面具有高性能。第一通道的较宽分数带宽（FBWs％）为34.3％，第二通道为38.6％，使所建议的双工器适合宽带应用。L频段和f ₂的谐振频率位于f ₁ = 1.6 GHz对于WiMAX应用，= 3 GHz。对于高达6.5 GHz（4 f ₁）的频率，最大谐波电平小于-20 dB 。最大组延迟在第一个通带处小于1.26 ns，在第二个通带处小于0.56 ns。拟议的双工器已制造并测量以进行验证。比较表明，测量结果和模拟结果都在合理的范围内。