skip to main content


Title: Switched Beam SIW Horn Arrays at 60 GHz for 360° Chip-to-Chip Communications
Switched beam horn arrays at 60 GHz based on the substrate integrated waveguide (SIW) technology are presented for use in reconfigurable chip-to-chip communications. Each array has eight identical printed horn elements. The elements can be individually excited to produce eight directive endfire beams, at an angular spacing of 45°, in the azimuth plane. The arrays enable each chip to communicate with its eight surrounding neighbors. The side and back lobes of the element radiation pattern, however, causes interference to chips that are in the unintended directions. The wireless links are analyzed using the measured and simulated transmission coefficients between the arrays in the line-of-sight (LoS) and non-line-of-sight (NLoS) directions.  more » « less
Award ID(s):
1708458
NSF-PAR ID:
10292083
Author(s) / Creator(s):
;
Date Published:
Journal Name:
2021 IEEE Radio and Wireless Symposium (RWS)
Page Range / eLocation ID:
39 to 42
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. null (Ed.)
    The link model of switched beam horn arrays at 60 GHz based on the substrate integrated waveguide (SIW) technology with 360° angular coverage is presented. Each array has eight identical printed horn elements. The elements are oriented 45° relative to one another and can be individually excited to produce eight endfire beams in the horizontal plane. The over-the-air (OTA) transmission coefficients are measured and simulated between two arrays, in the line-of-sight (LoS) and non-LoS (NLoS) directions. The phase centers (PCs) of the excited elements are determined from post-processing optimization of simulated far-fields and incorporated in the Friis equation to accurately model the transmission. 
    more » « less
  2. Abstract—Millimeter wave wireless spectrum deployments will allow vehicular communications to share high data rate vehicular sensor data in real-time.The highly directional nature of wireless links in millimeter spectral bands will require continuous channel measurements to ensure the transmitter (TX) and receiver (RX) beams are aligned to provide the best channel. Using real-world vehicular mmWave measurement data at 28GHz, we determine the optimal beam sweeping period, i.e. the frequency of the channel measurements,to align the RX beams to the best channel directions for maximizing the vehicle-to-infrastructure (V2I) throughput.We show that in a realistic vehicular traffic environment in Austin,TX, for a vehicle traveling at an average speed of 10.5mph,a beam sweeping period of 300 ms in future V2I communication standards would maximize theV2I throughput,using a system of four RX phased arrays that scanned the channel 360 degrees in the azimuth and 30 degrees above and below the boresight.We also investigate the impact of the number of active RX chains controlling the steerable phased arrays on V2I throughput. Reducing the number of RX chains controlling the phased arrays helps reduce the cost of the vehicular mmWave hardware while multiple RX chains, although more expensive,provide more robustness to beam direction changes at the vehicle,allowing near maximum throughput over a wide range of beam sweep periods.We show that the overhead of utilizing one RX chain instead of four leads to a10% drop in mean V2I throughput over six non-line- of-sight runs in real traffic conditions, with each run being 10 to 20 seconds long over a distance of 40 to 90 meters. Index Terms—mmWave;beam management;channel sound- ing; phased arrays;V2X;V2V;5G;sidelink 
    more » « less
  3. Prompted by the ever-growing demand for high-performance System-on-Chip (SoC) and the plateauing of CPU frequencies, the SoC design landscape is shifting. In a quest to offer programmable specialization, the adoption of tightly-coupled FPGAs co-located with traditional compute clusters has been embraced by major vendors. This CPU+FPGA architectural paradigm opens the door to novel hardware/software co-design opportunities. The key principle is that CPU-originated memory traffic can be re-routed through the FPGA for analysis and management purposes. Albeit promising, the side-effect of this approach is that time-critical operations—such as cache-line refills—are fulfilled by moving data over slower interconnects meant for I/O traffic. In this article, we introduce a novel principle named Cache Coherence Backstabbing to precisely tackle these shortcomings. The technique leverages the ability to include the FGPA in the same coherence domain as the core processing elements. Importantly, this enables Coherence-Aided Elective and Seamless Alternative Routing (CAESAR), i.e., seamless inspection and routing of memory transactions, especially cache-line refills, through the FPGA. CAESAR allows the definition of new memory programming paradigms. We discuss the intrinsic potentials of the approach and evaluate it with a full-stack prototype implementation on a commercial platform. Our experiments show an improvement of up to 29% in read bandwidth, 23% in latency, and 13% in pragmatic workloads over the state of the art. Furthermore, we showcase the first in-coherence-domain runtime profiler design as a use-case of the CAESAR approach. 
    more » « less
  4. Jelena Vuckovic (Ed.)
    On-chip broadband optical spectrometers that cover the entire tissue transparency window (λ = 650–1050 nm) with high resolution are highly demanded for miniaturized biosensing and bioimaging applications. The standard spatial heterodyne Fourier transform spectrometer (SHFTS) requires a large number of Mach–Zehnder interferometer (MZI) arrays to obtain a broad spectral bandwidth while maintaining high resolution. Here, we propose a novel type of SHFTS integrated with a subwavelength grating coupler (SWGC) for the dual-polarization bandpass sampling on the Si3N4 platform to solve the intrinsic trade-off limitation between the bandwidth and resolution of the SHFTS without having an outrageous number of MZI arrays or adding additional active photonic components. By applying the bandpass sampling theorem, the continuous broadband input spectrum is divided into multiple narrow-band channels through tuning the phase-matching condition of the SWGC with different polarization and coupling angles. Thereby, it is able to reconstruct each band separately far beyond the Nyquist criterion without aliasing error or degrading the resolution. We experimentally demonstrated the broadband spectrum retrieval results with the overall bandwidth coverage of 400 nm, bridging the wavelengths from 650 to 1050 nm, with a resolution of 2–5 nm. The bandpass sampling SHFTS is designed to have 32 linearly unbalanced MZIs with the maximum optical path length difference of 93 μm within an overall footprint size of 4.7 mm × 0.65 mm, and the coupling angles of SWGC are varied from 0° to 32° to cover the entire tissue transparency window. 
    more » « less
  5. Abstract While it is well recognized that both the Galactic interstellar extinction curves and the gas-phase abundances of dust-forming elements exhibit considerable variations from one sight line to another, as yet most of the dust extinction modeling efforts have been directed to the Galactic average extinction curve, which is obtained by averaging over many clouds of different gas and dust properties. Therefore, any details concerning the relationship between the dust properties and the interstellar environments are lost. Here we utilize the wealth of extinction and elemental abundance data obtained by space telescopes and explore the dust properties of a large number of individual sight lines. We model the observed extinction curve of each sight line and derive the abundances of the major dust-forming elements (i.e., C, O, Si, Mg, and Fe) required to be tied up in dust (i.e., dust depletion). We then confront the derived dust depletions with the observed gas-phase abundances of these elements and investigate the environmental effects on the dust properties and elemental depletions. It is found that for the majority of the sight lines the interstellar oxygen atoms are fully accommodated by gas and dust and therefore there does not appear to be a “missing oxygen” problem. For those sight lines with an extinction-to-hydrogen column density A V / N H ≳ 4.8 × 10 −22 mag cm 2 H −1 there are shortages of C, Si, Mg, and Fe elements for making dust to account for the observed extinction, even if the interstellar C/H, Si/H, Mg/H, and Fe/H abundances are assumed to be protosolar abundances augmented by Galactic chemical evolution. 
    more » « less