Substrate integrated waveguides optimized for ultrahigh-speed digital interconnects

Abstract

Abstract-This paper reports an experimental and computational study of substrate integrated waveguides (SIWs) optimized for use as ultrahigh-speed bandpass waveguiding digital interconnects. The novelty of this study resides in our successful design, fabrication, and testing of low-loss SIWs that achieve 100% relative bandwidths via optimal excitation of the dominant TE 10 mode and avoidance of the excitation of the TE 20 mode. Furthermore, our optimal structures maintain their 100% relative bandwidth while transmitting around 45 and 90 bends, and achieve measured crosstalk of better than 30 dB over the entire passband. We consider SIWs operating at center frequencies of 50 GHz, accommodating in principle data rates of greater than 50 Gb/s. These SIWs are 35% narrower in the transverse direction and provide a 20% larger relative bandwidth than our previously reported electromagnetic bandgap waveguiding digital interconnects. Since existing circuit-board technology permits dimensional reductions of the SIWs by yet another factor of 4 : 1 relative to the ones discussed here, bandpass operation at center frequencies approaching 200 GHz with data rates of 200 Gb/s are feasible. These data rates meet or exceed those expected eventually for proposed silicon photonic technologies.Index Terms-Finite-difference time-domain (FDTD) methods, multiprocessor interconnection, waveguide bends, waveguides.

Optimized Substrate Integrated Waveguide Bends for Ultra-High Speed Digital Interconnects

“…First we report measured and simulation results for an optimized straight SIW implemented in a double-sided circuit board of glass reinforced PTFE dielectric, Rogers RT/duroid® 5880 (ε r = 2.2, tan δ = 0.0009), and operating at a 50-GHz center frequency [8]. For all simulations, we have employed a high-resolution three-dimensional (3-D) finite difference time domain (FDTD) [9] grid having a space-cell size of 6.8 x 6.8 x 76 µm and a stable time-step near the Courant limit.…”

“…Those structures were similar to SIWs with the exception that each waveguide was bounded in the plane of propagation by double rows of vias. Here, we build upon our EBG waveguide work to show how SIWs can be optimally designed to realize easily constructed, compact waveguiding structures suitable for use as ultrahigh-speed wireless digital interconnects [8].…”

An Analysis Technique for Post-Wall Waveguides

“…Measurements of straight segments of metallic post-wall waveguides can be found in [6], [7]. More specifically, in [6] the loss of a post-wall waveguide is measured at 76.5 GHz.…”

Application of Generalized Multipole Technique to the Analysis of Discontinuities in Substrate Integrated Waveguides

“…It should be mentioned that to this date SIW discontinuities have been investigated using FDTD [5,8] and a commercial software [9]. In contrast to FDTD, GMT only requires the discretization of the boundaries, which exhibits therefore no problems with open space and provides exponential convergence for the smooth geometry of the vias.…”