A Novel Broadband CB-CPW to Microstrip Transition for Concept of Implementation in RF-Circuits

Abstract

A novel design of conductor backed CPW (CB-CPW) to microstrip line transition is introduced. The uniqueness of this design is that the ground plane of the bottom layer is complete, so the design overcomes the problems of the ground-shaped similar structures. Besides, wide bandwidth of the proposed transition (1-dB BW is 200%) is drastically noticeable. No micromachining technique is used during the design procedure of this structure, resulting in low cost and easy fabrication. Both the simple and the back to back structures for the transition are presented. Also a novel optimization technique for the design of a tapered region of the transition structure is demonstrated. Simulation and measurement results are presented in this paper in order to validate the proposed concept.