Low loss and broadband transition between substrate integrated waveguide and rectangular waveguide

In this article, a novel transition between substrate integrated waveguide (SIW) and rectangular waveguide is proposed. A pair of antipodal tapered probes is developed to convert the E-field of SIW to that of waveguide, acting as an antipodal dipole antenna to improve the performance of the SIW-to-waveguide transition. A back-to-back prototype of the proposed transition is fabricated and measured, the results show that the transition achieve a bandwidth of 51.1% from 23.7 to 40 GHz, and a size reduction of 75.3% compared to the SIW-to-waveguide transition using antipodal fin-line. A tolerance analysis is performed via the simulation to verify the reliability of this transition design. For further validation, the antipodal tapered probes are employed for the design of partially filled SIW-to-waveguide transition. From its experimental results, it demonstrates that the loss of a single SIW-to-waveguide is less than 0.26 dB over the frequency range of 24.9-40 GHz. In addition, such proposed SIW-to-waveguide transition is suitable for hermetic packaging due to the inherent property in transition structure. These results show that the proposed transition can offer the advantages of broad bandwidth, low loss, compact size, and stable performance at millimeter-wave frequencies. (c) 2015 Wiley Periodicals, Inc. Int J RF and Microwave CAE 26:54-61, 2016.