73 research outputs found

    A Review of CMOS Low Noise Amplifier for UWB System

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    A number of CMOS low noise amplifier (LNA) design for ultra-wideband (UWB) application had been produced with a various topology and techniques from year 2004 to 2016. The performance of LNA such as frequency bandwidth, noise figure, input and output matching and gain depend with the choice of the topology and technique used. Among the techniques introduced are current reuse, common source, resistive feedback, common gate, Chebyshev filter, distributed amplifier, folded cascade and negative feedback. This paper presents the collection of review about design of low noise amplifier used for UWB application in term of topology circuit. Thus, the problem and limitation of the CMOS LNA for UWB application are reviewed. Furthermore, recent developments of CMOS LNAs are examined and a comparison of the performance criteria of various topologies is presented

    A robust 2.4 GHz time-of-arrival based ranging system with sub-meter accuracy: feasibility study and realization of low power CMOS receiver

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    Draadloze sensornetwerken worden meer en meer aangewend om verschillende soorten informatie te verzamelen. De locatie, waar deze informatie verzameld is, is een belangerijke eigenschap en voor sommige toepassingen, zoals het volgen van personen of goederen, zelfs de meest belangrijke en mogelijkmakende factor. Om de positie van een sensor te bepalen, is een technologie nodig die de afstand tot een gekend referentiepunt schat. Door verschillende afstandsmetingen te combineren, is het mogelijk de absolute locatie van de node te berekenen

    Recent Advances in Neural Recording Microsystems

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    The accelerating pace of research in neuroscience has created a considerable demand for neural interfacing microsystems capable of monitoring the activity of large groups of neurons. These emerging tools have revealed a tremendous potential for the advancement of knowledge in brain research and for the development of useful clinical applications. They can extract the relevant control signals directly from the brain enabling individuals with severe disabilities to communicate their intentions to other devices, like computers or various prostheses. Such microsystems are self-contained devices composed of a neural probe attached with an integrated circuit for extracting neural signals from multiple channels, and transferring the data outside the body. The greatest challenge facing development of such emerging devices into viable clinical systems involves addressing their small form factor and low-power consumption constraints, while providing superior resolution. In this paper, we survey the recent progress in the design and the implementation of multi-channel neural recording Microsystems, with particular emphasis on the design of recording and telemetry electronics. An overview of the numerous neural signal modalities is given and the existing microsystem topologies are covered. We present energy-efficient sensory circuits to retrieve weak signals from neural probes and we compare them. We cover data management and smart power scheduling approaches, and we review advances in low-power telemetry. Finally, we conclude by summarizing the remaining challenges and by highlighting the emerging trends in the field

    Design of broadband inductor-less RF front-ends with high dynamic range for G.hn

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    System-on-Chip (SoC) was adopted in recent years as one of the solutions to reduce the cost of integrated systems. When the SoC solution started to be used, the final product was actually more expensive due to lower yield. The developments in integrated technology through the years allowed the integration of more components in lesser area with a better yield. Thus, SoCs became a widely used solution to reduced the cost of the final product, integrating into a single-chip the main parts of a system: analog, digital and memory. As integrated technology kept scaling down to allow a higher density of transistors and thus providing more functionality with the same die area, the analog RF parts of the SoC became a bottleneck to cost reduction as inductors occupy a large die area and do not scale down with technology. Hence, the trend moves toward the research and design of inductor-less SoCs that further reduce the cost of the final solution. Also, as the demand for home networking high-data-rates communication systems has increased over the last decade, several standards have been developed to satisfy the requirements of each application, the most popular being wireless local area networks (WLANs) based on the IEEE 802.11 standard. However, poor signal propagation across walls make WLANs unsuitable for high-speed applications such as high-definition in-home video streaming, leading to the development of wired technologies using the existing in-home infrastructure. The ITU-T G.hn recommendation (G.9960 and G.9961) unifies the most widely used wired infrastructures at home (coaxial cables, phone lines and power lines) into a single standard for high-speed data transmission of up to 1 Gb/s. The G.hn recommendation defines a unified networking over power lines, phone lines and coaxial cables with different plans for baseband and RF. The RF-coax bandplan, where this thesis is focused, uses 50 MHz and 100 MHz bandwidth channels with 256 and 512 carriers respectively. The center frequency can range from 350 MHz to 2450 MHz. The recommendation specifies a transmission power limit of 5 dBm for the 50 MHz bandplan and 8~dBm for the 100 MHz bandplan, therefore the maximum transmitted power in each carrier is the same for both bandplans. Due to the nature of an in-home wired environment, receivers that can handle both very large and very small amplitude signals are required; when transmitter and receiver are connected on the same electric outlet there is no channel attenuation and the signal-to-noise-plus-distortion ratio (SNDR) is dominated by the receiver linearity, whereas when transmitter and receiver are several rooms apart channel attenuation is high and the SNDR is dominated by the receiver noise figure. The high dynamic range specifications for these receivers require the use of configurable-gain topologies that can provide both high-linearity and low-noise for different configurations. Thus, this thesis has been aimed at researching high dynamic range broadband inductor-less topologies to be used as the RF front-end for a G.hn receiver complying with the provided specifications. A large part of the thesis has been focused on the design of the input amplifier of the front-end, which is the most critical stage as the noise figure and linearity of the input amplifier define the achievable overall specifications of the whole front-end. Three prototypes has been manufactured using a 65 nm CMOS process: two input RFPGAs and one front-end using the second RFPGA prototype.El "sistema en un chip" (SoC) fue adoptado recientemente como una de las soluciones para reducir el coste de sistemas integrados. Cuando se empezó a utilizar la solución SoC, el producto final era más caro debido al bajo rendimiento de producción. Los avances en tecnología integrada a lo largo de los años han permitido la integración de más componentes en menos área con mejoras en rendimiento. Por lo tanto, SoCs pasó a ser una solución ampliamente utilizada para reducir el coste del producto final, integrando en un único chip las principales partes de un sistema: analógica, digital y memoria. A medida que las tecnologías integradas se reducían en tamaño para permitir una mayor densisdad de transistores y proveer mayor funcionalidad con la misma área, las partes RF analógicas del SoC pasaron a ser la limitación en la reducción de costes ya que los inductores ocupan mucha área y no escalan con la tecnología. Por lo tanto, las tendencias en investigación se mueven hacia el diseño de SoCs sin inductores que todavía reducen más el coste final del producto. También, a medida que la demanda en sistemas de comunicación domésticos de alta velocidad ha crecido a lo largo de la última década, se han desarrollado varios estándares para satisfacer los requisitos de cada aplicación, siendo las redes sin hilos (WLANs) basadas en el estándar IEEE 802.11 las más populares. Sin embargo, una pobre propagación de señal a través de las paredes hacen que las WLANs sean inadecuadas para aplicaciones de alta-velocidad como transmisión de vídeo de alta definición en tiempo real, resultando en el desarrollo de tecnologías con hilos utilizando la infraestructura existente en los domicilios. La recomendación ITU-T G.hn (G.9960 and G.9961) unifica las principales infraestructuras con hilos domésticas (cables coaxiales, línias de teléfono y línias de electricidad) en un sólo estándar para la transmisión de datos hasta 1 Gb/s. La recomendación G.hn define una red unificada sobre línias de electricidad, de teléfono y coaxiales con diferentes esquemas para banda base y RF. El esquema RF-coax en el cual se basa esta tesis, usa canales con un ancho de banda de 50 MHz y 100 MHz con 256 y 512 portadoras respectivamente. La frecuencia centra puede variar desde 350 MHz hasta 2450 MHz. La recomendación especifica un límite en la potencia de transmisión de 5 dBm para el esquema de 50 MHz y 8 dBm para el esquema de 100 MHz, de tal forma que la potencia máxima por portadora es la misma en ambos esquemas. Debido a la estructura de un entorno doméstico con hilos, los receptores deben ser capaces de procesar señales con amplitud muy grande o muy pequeña; cuando transmisor y receptor están conectados en la misma toma eléctrica no hay atenuación de canal y el ratio de señal a rudio más distorsión (SNDR) está dominado por la linealidad del receptor, mientras que cuando transmisor y receptor están separados por varias habitaciones la atenuación es elevada y el SNDR está dominado por la figura de ruido del receptor. Los elevados requisitos de rango dinámico para este tipo de receptores requieren el uso de topologías de ganancia configurable que pueden proporcionar tanto alta linealidad como bajo ruido para diferentes configuraciones. Por lo tanto, esta tesis está encarada a la investigación de topologías sin inductores de banda ancha y elevado rango dinámico para ser usadas a la entrada de un receptor G.hn cumpliendo con las especificaciones proporcionadas. Una gran parte de la tesis se ha centrado en el diseño del amplificador de entrada al ser la etapa más crítica, ya que la figura de ruido y linealidad del amplificador de entrada definen lás máximas especificaciones que el sistema puede conseguir. Se han fabricado 3 prototipos con un proceso CMOS de 65 nm: 2 amplificadores y un sistema completo con amplificador y mezclador.Postprint (published version

    Passive and active circuits in cmos technology for rf, microwave and millimeter wave applications

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    The permeation of CMOS technology to radio frequencies and beyond has fuelled an urgent need for a diverse array of passive and active circuits that address the challenges of rapidly emerging wireless applications. While traditional analog based design approaches satisfy some applications, the stringent requirements of newly emerging applications cannot necessarily be addressed by existing design ideas and compel designers to pursue alternatives. One such alternative, an amalgamation of microwave and analog design techniques, is pursued in this work. A number of passive and active circuits have been designed using a combination of microwave and analog design techniques. For passives, the most crucial challenge to their CMOS implementation is identified as their large dimensions that are not compatible with CMOS technology. To address this issue, several design techniques – including multi-layered design and slow wave structures – are proposed and demonstrated through experimental results after being suitably tailored for CMOS technology. A number of novel passive structures - including a compact 10 GHz hairpin resonator, a broadband, low loss 25-35 GHz Lange coupler, a 25-35 GHz thin film microstrip (TFMS) ring hybrid, an array of 0.8 nH and 0.4 nH multi-layered high self resonant frequency (SRF) inductors are proposed, designed and experimentally verified. A number of active circuits are also designed and notable experimental results are presented. These include 3-10 GHz and DC-20 GHz distributed low noise amplifiers (LNA), a dual wideband Low noise amplifier and 15 GHz distributed voltage controlled oscillators (DVCO). Distributed amplifiers are identified as particularly effective in the development of wideband receiver front end sub-systems due to their gain flatness, excellent matching and high linearity. The most important challenge to the implementation of distributed amplifiers in CMOS RFICs is identified as the issue of their miniaturization. This problem is solved by using integrated multi-layered inductors instead of transmission lines to achieve over 90% size compression compared to earlier CMOS implementations. Finally, a dual wideband receiver front end sub-system is designed employing the miniaturized distributed amplifier with resonant loads and integrated with a double balanced Gilbert cell mixer to perform dual band operation. The receiver front end measured results show 15 dB conversion gain, and a 1-dB compression point of -4.1 dBm in the centre of band 1 (from 3.1 to 5.0 GHz) and -5.2 dBm in the centre of band 2 (from 5.8 to 8 GHz) with input return loss less than 10 dB throughout the two bands of operation

    Low-power CMOS front-ends for wireless personal area networks

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    The potential of implementing subthreshold radio frequency circuits in deep sub-micron CMOS technology was investigated for developing low-power front-ends for wireless personal area network (WPAN) applications. It was found that the higher transconductance to bias current ratio in weak inversion could be exploited in developing low-power wireless front-ends, if circuit techniques are employed to mitigate the higher device noise in subthreshold region. The first fully integrated subthreshold low noise amplifier was demonstrated in the GHz frequency range requiring only 260 ÎĽW of power consumption. Novel subthreshold variable gain stages and down-conversion mixers were developed. A 2.4 GHz receiver, consuming 540 ÎĽW of power, was implemented using a new subthreshold mixer by replacing the conventional active low noise amplifier by a series-resonant passive network that provides both input matching and voltage amplification. The first fully monolithic subthreshold CMOS receiver was also implemented with integrated subthreshold quadrature LO (Local Oscillator) chain for 2.4 GHz WPAN applications. Subthreshold operation, passive voltage amplification, and various low-power circuit techniques such as current reuse, stacking, and differential cross coupling were combined to lower the total power consumption to 2.6 mW. Extremely compact resistive feedback CMOS low noise amplifiers were presented as a cost-effective alternative to narrow band LNAs using high-Q inductors. Techniques to improve linearity and reduce power consumption were presented. The combination of high linearity, low noise figure, high broadband gain, extremely small die area and low power consumption made the proposed LNA architecture a compelling choice for many wireless applications.Ph.D.Committee Chair: Laskar, Joy; Committee Member: Chakraborty, Sudipto; Committee Member: Chang, Jae Joon; Committee Member: Divan, Deepakraj; Committee Member: Kornegay, Kevin; Committee Member: Tentzeris, Emmanoui
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