A novel wideband back‐to‐back microstrip‐to‐air‐filled substrate integrated waveguide (AFSIW) transition with controllable band‐pass performance is presented. The wideband transition is constructed by a gradient microstrip and a section of widened partially dielectric‐filled AFSIW. The sharp rejection performance above the pass band is achieved by taking advantage of the notch characteristics of the widened partially dielectric‐filled AFSIW section. The lower stop band is determined by the cut‐off characteristic of the intermediate AFSIW between the back‐to‐back transitions. The relationship between the band‐pass response and the dimensional parameters of the transition is investigated. A prototype is designed, manufactured and measured. The measured fractional bandwidth (FBW) is 57.63% centered at 14.75 GHz. The suppression over 20 ~ 25 GHz is better than 25 dB, and a transmission zero with a suppression of 51.7 dB is introduced at 1 GHz away from the upper‐edge frequency of the pass band.

中文翻译：

---

具有可控带通性能的宽带微带到充气衬底集成波导过渡

提出了具有可控带通性能的新型宽带背对背微带到空气填充衬底集成波导（AFSIW）过渡。宽带过渡由梯度微带和一段加宽的部分电介质填充的AFSIW构成。通过利用加宽的部分电介质填充的AFSIW截面的陷波特性，可以在通带以上实现出色的抑制性能。较低的阻带由背对背转换之间的中间AFSIW的截止特性确定。研究了带通响应与跃迁的尺寸参数之间的关系。设计，制造和测量原型。测得的小数带宽（FBW）以57.63％为中心，集中在14.75 GHz。