Extended SIW for ${\rm TE}_{m0}$ and ${\rm TE}_{0n}$ Modes and Slotline Excitation of the

A substrate integrated guide which allows the propagation of both TE_m0 and TE_0n modes is presented, the Extended Substrate Integrated Waveguide (ESIW). Its structure combines the working principles of SIWs and SINRD guides. While the performances of the ESIW with TE_m0 modes are the same as conventional SIWs, they are better than SINRD guides concerning TE_0n-like modes. In addition, a novel slotline-based excitation is proposed to launch the mode in the ESIW. This solution alleviates some of the problems encountered in current structures used to excite -like modes, e.g., spurious mode excitation or complicated manufacturing designs. Measurements of a slotline fed ESIW are presented validating the proposed concepts.