IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES, VOL. 58, NO. 7, JULY 2010
Design and Analysis of 1-D Uniform and Chirped Electromagnetic Bandgap Structures in Substrate-Integrated Waveguides
Joshua D. Schwartz, Member, IEEE, Ramesh Abhari, Senior Member, IEEE, David V. Plant, Fellow, IEEE, and José Azaña, Member, IEEE
Abstract—We demonstrate the creation of an electromagnetic bandgap (stopband) within the passband of the fundamental mode of a substrate-integrated waveguide. The bandgap is achieved by periodically modulating the waveguide width using the metallic plated vias that form the effective waveguide sidewall. We describe the design of such a structure, noting that, compared with previously demonstrated 1-D transmission-line electromagnetic bandgap structures, the resonant bandgap frequency is more signiﬁcantly affected by the amplitude (depth) of the modulation of the waveguide width. We explain this result using classical circuit theory and describe a model-based approach to predicting device behavior. We present measured results for several designed -band using smooth and square-like modulastructures in the tions of the waveguide width. We demonstrate both uniform and linearly chirped (dispersive) implementations; the latter structures yield broadband linear group delays in the reﬂected band. Index Terms—Dispersion, millimeter-wave waveguides, periodic structures, photonic bandgap, planar waveguides, waveguide ﬁlters.
I. INTRODUCTION UBSTRATE integrated waveguides (SIWs), also known as post-wall waveguides, have emerged as a promising new interconnect for microwave and millimeter-wave signals, in part because they combine the high- -factor and low-loss merits of traditional rectangular waveguides with the simplicity of planar fabrication and low-cost integration. SIWs use fencepost arrangements of metallized vias of sufﬁciently close spacing such
Manuscript received December 02, 2009; revised April 12, 2010; accepted...