Complementary spiral resonators for ultrawideband suppression of simultaneous switching noise in high-speed circuits

Cataloged from PDF version of article.In this paper, a novel concept for ultra-wideband simultaneous switching noise (SSN) mitigation in high-speed printed circuit boards (PCBs) is proposed. Using complementary spiral resonators (CSRs) etched on only a single layer of the power plane and cascaded co-centrically around the noise port, ultra-wideband SSN suppression by 30 dB is achieved in a frequency span ranging from 340 MHz to beyond 10 GHz. By placing a slit in the co-centric rings, lower cut-off frequency is reduced to 150 MHz, keeping the rest of the structure unaltered. Finally, the power plane structure with modified complementary spiral resonators (MCSRs) is designed, fabricated, and evaluated experimentally. Measurement and simulation results are in well-agreement

A Miniaturized Patch Antenna by Using a CSRR Loading Plane

This paper presents a design methodology for the implementation of a miniaturized square patch antenna and its circuit model for 5.15 GHz ISM band. The miniaturization is achieved by employing concentric complementary split ring resonator (CSRR) structures in between the patch and ground plane. The results are compared with the traditional square patch antenna in terms of area, bandwidth, and efficiency. The area is reduced with a ratio of 1/4 with respect to the traditional patch. The miniaturized square patch antenna has an efficiency, bandwidth, and reflection coefficient of 78%, 0.4%, and -16 dB, respectively. The measurement and circuit modeling results show a good agreement with the full-wave electromagnetic simulations. © 2015 Mehrab Ramzan and Kagan Topalli

Wideband 'black silicon' for mid-infrared applications

In this paper, we investigate the absorption of mid-infrared light by low resistivity silicon textured via deep reactive ion etching. An analytical description of the wave propagation in black silicon texture is presented, showing agreement with the experiment and the computational analysis. We also study the dependence of absorption spectrum of black silicon structure on the electrical conductivity of silicon substrate. The structures investigated unveil wideband, all-silicon infrared absorbers applicable for infrared imaging and spectroscopy with simple CMOS compatible fabrication suitable for optoelectronic integration. © 2017 IOP Publishing Ltd

High-conductivity silicon based spectrally selective plasmonic surfaces for sensing in the infrared region

Plasmonic perfect absorbers have found a wide range of applications in imaging, sensing, and light harvesting and emitting devices. Traditionally, metals are used to implement plasmonic structures. For sensing applications, it is desirable to integrate nanophotonic active surfaces with biasing and amplification circuitry to achieve monolithic low cost solutions. Commonly used plasmonic metals such as Au and Ag are not compatible with standard silicon complementary metal-oxide-semiconductor (CMOS) technology. Here we demonstrate plasmonic perfect absorbers based on high conductivity silicon. Standard optical lithography and reactive ion etching techniques were used for the patterning of the samples. We present computational and experimental results of surface plasmon resonances excited on a silicon surface at normal and oblique incidences. We experimentally demonstrate our absorbers as ultra-low cost, CMOS-compatible and efficient refractive index sensing surfaces. The experimental results reveal that the structure exhibits a sensitivity of around 11 000 nm/RIU and a figure of merit of up to 2.5. We also show that the sensing performance of the structure can be improved by increasing doping density. � 2016 IOP Publishing Ltd

Atomic layer deposition synthesized TiOx thin films and their application as microbolometer active materials

This paper demonstrates the possible usage of TiOx thin films synthesized by atomic layer deposition as a microbolometer active material. Thin film electrical resistance is investigated as a function of thermal annealing. It is found that the temperature coefficient of resistance values can be controlled by coating/annealing processes, and the value as high as -9%/K near room temperature is obtained. The noise properties of TiOx films are characterized. It is shown that TiOx films grown by atomic layer deposition technique could have a significant potential to be used as a new active material for microbolometer-based applications. © 2016 American Vacuum Society

Plasmonically enhanced metal-insulator multistacked photodetectors with separate absorption and collection junctions for near-infrared applications

Plasmonically enhanced metal-insulator-metal (MIM) type structures are popular among perfect absorbers and photodetectors in which the field enhancement (for increased absorption) mechanism is directly coupled with collection (photocurrent) processes. In this work we propose a device structure that decouples absorption and collection parts for independent optimization. Double-stacked MIM (i.e. MIMIM) photodetectors operating in the near-infrared (NIR) spectrum up to 1200 nm wavelength are demonstrated. In the absorbing MIM (at the top side), we have used Silver nanoparticles resulting from dewetting, yielding a very low reflection of 10% for the most part of the 400 to 1000 nm wavelength range. An unconventional plasmonic material, Chromium, exhibits an absorption peak of over 80% at 1000 nm. The complete device has been fabricated and the photo-collection tunneling MIM (at the bottom) suppresses the leakage current by metal workfunction difference. An optimized stack consisting of Silver-Hafnium Oxide-Chromium-Aluminum Oxide-Silver nanoparticles (from bottom to top) yields a dark current of 7 nA and a photoresponsivity peak of 0.962 mA/W at 1000 nm and a full width at half maximum of 300 nm, while applied bias is 50 mV and device areas are 300 μm × 600 μm. © 2017 The Author(s)

All-Silicon Ultra-Broadband Infrared Light Absorbers

Absorbing infrared radiation efficiently is important for critical applications such as thermal imaging and infrared spectroscopy. Common infrared absorbing materials are not standard in Si VLSI technology. We demonstrate ultra-broadband mid-infrared absorbers based purely on silicon. Broadband absorption is achieved by the combined effects of free carrier absorption, and vibrational and plasmonic absorption resonances. The absorbers, consisting of periodically arranged silicon gratings, can be fabricated using standard optical lithography and deep reactive ion etching techniques, allowing for cost-effective and wafer-scale fabrication of micro-structures. Absorption wavebands in excess of 15 micrometers (5-20 μm) are demonstrated with more than 90% average absorptivity. The structures also exhibit broadband absorption performance even at large angles of incidence (θ = 50°), and independent of polarization. © 2016 The Author(s)

Practical multi-featured perfect absorber utilizing high conductivity silicon

We designed all-silicon, multi-featured band-selective perfect absorbing surfaces based on CMOS compatible processes. The center wavelength of the band-selective absorber can be varied between 2 and 22 μm while a bandwidth as high as 2.5 μm is demonstrated. We used a silicon-on-insulator (SOI) wafer which consists of n-type silicon (Si) device layer, silicon dioxide (SiO2) as buried oxide layer, and n-type Si handle layer. The center wavelength and bandwidth can be tuned by adjusting the conductivity of the Si device and handle layers as well as the thicknesses of the device and buried oxide layers. We demonstrate proof-of-concept absorber surfaces experimentally. Such absorber surfaces are easy to microfabricate because the absorbers do not require elaborate microfabrication steps such as patterning. Due to the structural simplicity, low-cost fabrication, wide spectrum range of operation, and band properties of the perfect absorber, the proposed multi-featured perfect absorber surfaces are promising for many applications. These include sensing devices, surface enhanced infrared absorption applications, solar cells, meta-materials, frequency selective sensors and modulators. © 2016 IOP Publishing Ltd

A performance-enhanced planar Schottky diode for Terahertz applications: An electromagnetic modeling approach

In this paper, we present the electromagnetic modeling of a performance-enhanced planar Schottky diode for applications in terahertz (THz) frequencies. We provide a systematic simulation approach for analyzing our Schottky diode based on finite element method and lumped equivalent circuit parameter extraction. Afterward, we use the developed model to investigate the effect of design parameters of the Schottky diode on parasitic capacitive and resistive elements. Based on this model, device design has been improved by deep-trench formation in the substrate and using a closed-loop junction to reduce the amount of parasitic capacitance and spreading resistance, respectively. The results indicate that cut-off frequency can be improved from 4.1 to 14.1 THz. Finally, a scaled version of the diode is designed, fabricated, and well characterized to verify the validity of this modeling approach. Copyright © 2017 Cambridge University Press and the European Microwave Association

Seed Layer Assisted Hydrothermal Deposition of Low-resistivity ZnO Thin Films

In this work, we describe the combination of hydrothermal and atomic layer deposition (ALD) for growing low-resistivity ZnO polycrystalline continuous films. The effect of the thickness of ALD seed layers on the morphology of the hydrothermal ZnO films was studied. It was shown that ZnO films hydrothermally deposited on very thin seed layer consist of separate nanorods but in the case of 20 nm seed layer ZnO films transform to uniform continuous layers comprising of closely packed vertically aligned crystallites. Photoluminescence spectra were shown to exhibit broad band behavior in the visible range, corresponding to radiative recombination processes via oxygen defects of ZnO crystalline lattice, and narrow band in the UV region, associated with band-to-band recombination processes. It was shown that the resistivity of the obtained ZnO films is decreased gradually with the increase of ZnO films thickness and determined by the presence of crystal lattice defects in the seed layer. Copyright © Materials Research Society 2017