430 research outputs found

    A 25% Tuning Range 7.5-9.4 GHz Oscillator With 194 FoM<sub>T</sub>and 400 kHz 1/f Corner in 40nm CMOS Technology

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    An 8-GHz VCO with class-F23 operation was realized in a 40 nm CMOS technology without ultra-thick metals. The class-F23 operation was enabled in a transformer-based LC tank to allow multiple impedance peaks in the common mode (CM) and the differential mode (DM) excitation. With the additional resonance at 2nd2^{nd} and 3rd3^{rd} harmonic frequency, the circuit noise to phase-noise conversion and 1/f noise up-conversion are reduced significantly. In a 40 nm CMOS technology without ultra-thick metal, a patterned shielding structure was proposed to improve the inductor quality factor. A combined varactor and capacitor array is proposed to provide accurate matching for a desired resonance frequency ratio, reducing AM-FM conversion and it achieves a broad tuning range. With the proposed transformer-based LC bank and class-F23 operation, the oscillator achieves a phase noise of -150.8 dBc/Hz at 10 MHz offset from a 1.85 GHz carrier after an on-chip /4 divider, and the measured 1/f3 flicker noise corner is around 400 kHz. The oscillator core covers a 7.5-9.4 GHz frequency range for a 25% tuning range.</p

    Survey on individual components for a 5 GHz receiver system using 130 nm CMOS technology

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    La intención de esta tesis es recopilar información desde un punto de vista general sobre los diferentes tipos de componentes utilizados en un receptor de señales a 5 GHz utilizando tecnología CMOS. Se ha realizado una descripción y análisis de cada uno de los componentes que forman el sistema, destacando diferentes tipos de configuraciones, figuras de mérito y otros parámetros. Se muestra una tabla resumen al final de cada sección, comparando algunos diseños que se han ido presentando a lo largo de los años en conferencias internacionales de la IEEE.The intention of this thesis is to gather information from an overview point about the different types of components used in a 5 GHz receiver using CMOS technology. A review of each of the components that form the system has been made, highlighting different types of configurations, figure of merits and parameters. A summary table is shown at the end of each section, comparing many designs that have been presented over the years at international conferences of the IEEE.Departamento de Ingeniería Energética y FluidomecánicaGrado en Ingeniería en Electrónica Industrial y Automátic

    Low power digitally controlled oscillator for IoT applications

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    This work is focused on the design of a Low Power CMOS DCO for IEEE 802.11ah in IoT applications. The design methodology is based on the Unified current-control model (UICM), which is a physics-based model and enables an accurate all-region model of the operation of the device. Additionally, a transformer-based resonator has been used to solve the low-quality factor issue of integrated inductors. Two digitally controlled oscillators (DCO) have been implemented to show the advantages of utilizing a transformedbased resonator and the methodology based on the UICM model. These designs aim for the operation in low voltage supply (VDD) since VDD scaling is a trend in systems-onchip (SoCs), in which the circuitry is mostly digital. Despite the degradation caused by VDD scaling, new RF and analog circuits must deliver similar performance of the older CMOS nodes. The first DCO design was a low power LC-tank DCO, implemented in 40nm bulk-CMOS. The first design presented a DCO operating at 45% of the nominal VDD without compromise the performance. By reducing the VDD below the nominal value, this DCO reduces power consumption, which is a crucial feature for IoT circuits. The main contribution of this first DCO is the reduction of VDD scaling impact on the phase-noise do the DCO. The LC-based DCO operates from 1.8 to 1.86 GHz. At the maximum frequency and 0.395V VDD, the power consumption is a mere 380 W with a phase-noise of -119.3 dBc/Hz at 1 MHz. The circuit occupies an area of 0.46mm2 in 40 nm CMOS, mostly due to the inductor. The second DCO design was a low-power transformer-based DCO design, implemented in 28nm bulk-CMOS. This second design aims for the VDD reduction to below 0.3 V. Operating in a frequency range similar to the LC-based DCO, the transformer-based DCO operated with 0.280V VDD with a power consumption of 97 W. Meanwhile, the phase-noise was -101.95 dBc/Hz at 1 MHz. Even in the worst-case scenario (i.e., slow-slow and 85oC), this second DCO was able to operate at 0.330V VDD, consuming 126 W, while it keeps a similar phase-noise performance of the typical case. The core circuit occupies an area of 0.364 mm2.Este trabalho objetiva o projeto de um DCO de baixa potência em CMOS para aplicações de IoT e aderentes ao padrão IEEE 802.11ah. A metodologia de projeto é baseada no modelo de controle de corrente unificado (UICM), que é um modelo com embasamento físico que permite uma operação precisa em todas as regiões de operação do dispositivo. Adicionalmente, é utilizado um ressonador baseado em transformador visando solucionar os problemas provenientes do baixo fator de qualidade de indutores integrados. Para destacar as melhorias obtidas com o projeto do ressonador baseado em transformador e com a metodologia baseada no modelo UICM, dois projetos de DCO são realizados. Esses projetos visam a operação com baixa tensão de alimentação (VDD), uma vez que o escalonamento do VDD é uma tendência em sistemas em chip (SoCs), em que o circuito é majoritariamente digital. Independente da degradação causada pelo escalonamento de VDD, circuitos analógicos e de RF atuais devem oferecer desempenho semelhante ao alcançado em tecnologias CMOS mais antigas. O primeiro projeto foi um DCO de baixa potência com tanque LC, implementado em tecnologia bulk-CMOS de 40nm. O primeiro projeto apresentou uma operação a 45% do VDD nominal sem comprometer o desempenho. Ao reduzir o VDD abaixo do valor nominal, este DCO reduz o consumo de energia, que é uma característica crucial para circuitos IoT. A principal contribuição deste DCO é a redução do impacto do escalonamento do VDD no ruído de fase. O DCO com tanque LC opera de 1,8 a 1,86 GHz. Na frequência máxima e com VDD de apenas 0,395V, o consumo de energia é 380 W e o ruído de fase é -119,3 dBc/Hz a 1 MHz. O circuito ocupa uma área de 0.46mm2 em processo CMOS de 40 nm. O segundo projeto foi um DCO de baixa potência baseado em transformador, implementado em tecnologia bulk- CMOS de 28nm. Este projeto visa a redução de VDD abaixo de 0,3 V. Operando em uma faixa de frequência semelhante ao primeiro DCO, o DCO baseado em transformador opera com VDD de 0,280V e com consumo de potência de 97 W. O ruído de fase foi de -101,95 dBc/Hz a 1 MHz. Mesmo no pior caso de processo, este DCO opera a um VDD de 0,330V, consumindo 126 W, com o ruído de fase semelhante ao caso típico. O circuito ocupa uma área de 0.364mm2

    An Energy-Efficient Reconfigurable Mobile Memory Interface for Computing Systems

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    The critical need for higher power efficiency and bandwidth transceiver design has significantly increased as mobile devices, such as smart phones, laptops, tablets, and ultra-portable personal digital assistants continue to be constructed using heterogeneous intellectual properties such as central processing units (CPUs), graphics processing units (GPUs), digital signal processors, dynamic random-access memories (DRAMs), sensors, and graphics/image processing units and to have enhanced graphic computing and video processing capabilities. However, the current mobile interface technologies which support CPU to memory communication (e.g. baseband-only signaling) have critical limitations, particularly super-linear energy consumption, limited bandwidth, and non-reconfigurable data access. As a consequence, there is a critical need to improve both energy efficiency and bandwidth for future mobile devices.;The primary goal of this study is to design an energy-efficient reconfigurable mobile memory interface for mobile computing systems in order to dramatically enhance the circuit and system bandwidth and power efficiency. The proposed energy efficient mobile memory interface which utilizes an advanced base-band (BB) signaling and a RF-band signaling is capable of simultaneous bi-directional communication and reconfigurable data access. It also increases power efficiency and bandwidth between mobile CPUs and memory subsystems on a single-ended shared transmission line. Moreover, due to multiple data communication on a single-ended shared transmission line, the number of transmission lines between mobile CPU and memories is considerably reduced, resulting in significant technological innovations, (e.g. more compact devices and low cost packaging to mobile communication interface) and establishing the principles and feasibility of technologies for future mobile system applications. The operation and performance of the proposed transceiver are analyzed and its circuit implementation is discussed in details. A chip prototype of the transceiver was implemented in a 65nm CMOS process technology. In the measurement, the transceiver exhibits higher aggregate data throughput and better energy efficiency compared to prior works

    Design of a 41.14-48.11 GHz triple frequency based VCO

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    © 2019 by the authors. Licensee MDPI, Basel, Switzerland. Growing deployment of more efficient communication systems serving electric power grids highlights the importance of designing more advanced intelligent electronic devices and communication-enabled measurement units. In this context, phasor measurement units (PMUs) are being widely deployed in power systems. A common block in almost all PMUs is a phase locked oscillator which uses a voltage controlled oscillator (VCO). In this paper, a triple frequency based voltage controlled oscillator is presented with low phase noise and robust start-up. The VCO consists of a detector, a comparator, and triple frequency. A VCO starts-up in class AB, then steadies oscillation in class C with low current oscillation. The frequency of the VCO, which is from 13.17 GHz to 16.03 GHz, shows that the frequency is tripling to 41.14-48.11 GHz. Therefore, its application is not limited to PMUs. This work has been simulated in a standard 0.18 µm CMOS process. The simulated VCO achieves a phase noise of -99.47 dBc/Hz at 1 MHz offset and -121.8 dBc/Hz at 10 MHz offset from the 48.11 GHz carrier

    A Recofigurable Tri-Band Interconnect for Future Network-On-Chip

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    The scaling of CMOS feature sizes has yielded the capability of integrating heterogeneous intellectual properties (IPs) like graphics processing units (GPUs), digital signal processors (DSPs) and central processing units (CPUs) on a single die. The collection of multiple IPs on a single die presents a problem of reliable communication due to congestion. The infrastructure that facilitates and manages communication among IPs is referred to as a network-on-chip (NoC). Its ultimate goal should be low latency with negligible power and area consumption. Unfortunately, as CMOS feature sizes have been scaling smaller, this has exacerbated latency and signal degradation due to increasing on-chip channel resistance. Furthermore, contemporary interfaces use baseband-only signaling and have critical limitations like exponential energy consumption, limited bandwidth and non-reconfigurable data access.;In this work, we propose an energy efficient tri-band (baseband + 2 RF bands) signaling interface that is capable of simultaneous bi-directional communication and reconfigurable data access. Additionally, communication is accomplished through a shared transmission line which reduces the overall number of global interconnections. As a result, this reduces area consumption and mitigates interconnection complexity. The primary signicance of this interconnect configuration compared to contemporary designs is an increase of bandwidth and energy efficiency.;The interconnect design is composed of a baseband transceiver and two RF (10Ghz and 20GHz) transceivers. The RF transceivers utilize amplitude-shift keying (ASK) modulation scheme. ASK modulation allows ease of circuit design, but most importantly it can be used for noncoherent communication, which we implemented in this system. Noncoherent ASK modulation is area conservative and power efficient since there is no longer a need for power-hungry frequency synthesizers. Moreover, noncoherent ASK demodulation accomplishes direct-down conversation through a passive self-mixer for additional power savings.;The results from our work show that a multi-band interconnect is a suitable remedy for future NoC communication that has been reaching its bandwidth limitation with baseband-only signaling. In conclusion, this work demonstrates a sustainable balance of energy efficiency and increased bandwidth for future on-chip interconnect designs
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