Crosstalk in Substrate Integrated Waveguides

Substrate integrated waveguide (SIW) represents an emerging technology for the implementation of waveguide components in planar form, in the frequency range of microwaves and mm-waves. While the SIW is similar to a classical metallic waveguide, the structure is not completely shielded and may be subject to a radiation leakage. This leakage could cause a crosstalk between adjacent SIW interconnects. While for other structures, e.g., microstrip lines, the determination of the crosstalk was widely investigated, no quantitative relationship was previously derived in the case of SIW structures. In order to fill this gap, this paper presents for the first time the derivation of a formula to calculate the crosstalk in SIW structures.

I. Introduction

Substrate waveguides (SIWs) are one of the best candidate to realize high-performance and low-cost microwave and mm-wave circuits. They offer the advantages of other planar technologies, e.g., microstrips and coplanar lines, such as low costs, low mass and volume, while achieving superior performance in terms of quality factor [1]. SIWs are suitable to implement several different type of passive and active devices and circuits [2]. In addition, SIWs are naturally suited for high integration approaches, providing the possibility to monolithically integrate all components in a single substrate, with no need of interconnects or transitions between elements fabricated with different technologies, thus dramatically reducing losses and parasitic [3]. This may lead to the use of SIWs also for high-speed interconnects [4], [5].