Design of a 2.4 Ghz BAW-Based CMOS Transmitter

In recent years, bulk acoustic wave resonators (BAW) in combination with RF circuits have shown a big potential in achieving the low-power consumption and miniaturization level required to address wireless sensor nodes (WSN) applications. A lot of work has been focused on the receiver side, by integrating BAW resonators with low noise amplifiers (LNA) and in frequency synthesis with the design of BAW-based local oscillators, most of them working at fixed frequency due to their limited tuning range. At the architectural level, this has forced the implementation of several single channel transceivers. This thesis aims at exploring the use of BAW resonators in the transmitter, proposing an architecture capable of taking full advantage of them. The main objective is to develop a transmitter for WSN multi-channel applications able to cover the whole 2.4 GHz ISM band and enable the compatibility with wide-spread standards like Bluetooth and Bluetooth Low Energy. Typical transmissions should thus range from low data rates (typically tens of kb/s) to medium data rates (1 Mb/s), with FSK and GFSK modulation schemes, should be centered on any of the channels provided by these standards and cover a maximum transmission range of some tens of meters. To achieve these targets and circumvent the limited tuning range of the BAW oscillator, an up-conversion transmitter using wide IF is used. The typical spurs problems related to this transmitter architecture are addressed by using a combined suppression based on SSB mixing and selective amplification. The latter is achieved by cointegration of a high efficiency power amplifier with BAW resonators, which allows performing spurs filtering while preserving the efficiency. In particular the selective amplifier is designed by including in the PA analysis the BAW resonator parameters, which allows integrating the BAW filter into the passive network loading the amplifier, participating in the drain voltage shaping. Finally, the frequency synthesis section uses a fractional division plus LC PLL filtering and further integer division to generate the IF signals and exploit the very-low BAW oscillator phase noise. The transmitter has been integrated in a 0.18 µm standard digital CMOS technology. It allows addressing the whole 80 MHz wide 2.4 GHz ISM band. The unmodulated RF frequency carrier demonstrates a very-low phase noise of –136 dBc/Hz at 1 MHz offset. The IF spurs are maintained lower than –48 dBc, satisfying the international regulations for output power up to 10 dBm without the use of any quadrature error compensation in the transmitter. This is achieved thanks to the rejection provided by the SSB mixer and the selective amplifier, which can reach drain efficiency of up to 24% with integrated inductances, including the insertion losses of the BAW filter. The transmitter consumes 35.3 mA at the maximum power of 5.4 dBm under 1.6 V (1.2 V for the PA), while transmitting a 1 Mb/s GFSK signal and complying with both Bluetooth and Bluetooth Low Energy relative and absolute spectrum requirements

Low-Power High-Data-Rate Transmitter Design for Biomedical Application

Ph.DDOCTOR OF PHILOSOPH

System-level design and RF front-end implementation for a 3-10ghz multiband-ofdm ultrawideband receiver and built-in testing techniques for analog and rf integrated circuits

This work consists of two main parts: a) Design of a 3-10GHz UltraWideBand (UWB) Receiver and b) Built-In Testing Techniques (BIT) for Analog and RF circuits. The MultiBand OFDM (MB-OFDM) proposal for UWB communications has received significant attention for the implementation of very high data rate (up to 480Mb/s) wireless devices. A wideband LNA with a tunable notch filter, a downconversion quadrature mixer, and the overall radio system-level design are proposed for an 11-band 3.4-10.3GHz direct conversion receiver for MB-OFDM UWB implemented in a 0.25mm BiCMOS process. The packaged IC includes an RF front-end with interference rejection at 5.25GHz, a frequency synthesizer generating 11 carrier tones in quadrature with fast hopping, and a linear phase baseband section with 42dB of gain programmability. The receiver IC mounted on a FR-4 substrate provides a maximum gain of 67-78dB and NF of 5-10dB across all bands while consuming 114mA from a 2.5V supply. Two BIT techniques for analog and RF circuits are developed. The goal is to reduce the test cost by reducing the use of analog instrumentation. An integrated frequency response characterization system with a digital interface is proposed to test the magnitude and phase responses at different nodes of an analog circuit. A complete prototype in CMOS 0.35mm technology employs only 0.3mm2 of area. Its operation is demonstrated by performing frequency response measurements in a range of 1 to 130MHz on 2 analog filters integrated on the same chip. A very compact CMOS RF RMS Detector and a methodology for its use in the built-in measurement of the gain and 1dB compression point of RF circuits are proposed to address the problem of on-chip testing at RF frequencies. The proposed device generates a DC voltage proportional to the RMS voltage amplitude of an RF signal. A design in CMOS 0.35mm technology presents and input capacitance <15fF and occupies and area of 0.03mm2. The application of these two techniques in combination with a loop-back test architecture significantly enhances the testability of a wireless transceiver system

Telecommunications system of a CubeSat satellite

This Final degree's thesis is done under the UPC-Canadà program in which the author realizes his last degree year in Montréal, Canada, to the Polytechnique de Montréal university under the supervision of Dr. Giovanni Beltrame being part of his laboratory Mistlab and also on the Polyorbite group of students. Polyorbite is an organization that participates in the biannual contest CSDC (Canadian Satellite Design Challenge) that consists on the realization from 0 of a 3U CubeSat by undergraduate and master students. By the start of this thesis on September 2016, the contest was in the middle of the 2014-2016 iteration without having almost nothing on the telecommunication part, having just 2 semesters for design, build and test an entirely telecommunications system, suitable for the satellite purpose, until June 2016 in which the final presentations of the contest took place on Ottawa. The purpose of this thesis is then an early design of a telecommunications system for a CubeSat satellite

Low Power Circuit Design in Sustainable Self Powered Systems for IoT Applications

The Internet-of-Things (IoT) network is being vigorously pushed forward from many fronts in diverse research communities. Many problems are still there to be solved, and challenges are found among its many levels of abstraction. In this thesis we give an overview of recent developments in circuit design for ultra-low power transceivers and energy harvesting management units for the IoT. The first part of the dissertation conducts a study of energy harvesting interfaces and optimizing power extraction, followed by power management for energy storage and supply regulation. we give an overview of the recent developments in circuit design for ultra-low power management units, focusing mainly in the architectures and techniques required for energy harvesting from multiple heterogeneous sources. Three projects are presented in this area to reach a solution that provides reliable continuous operation for IoT sensor nodes in the presence of one or more natural energy sources to harvest from. The second part focuses on wireless transmission, To reduce the power consumption and boost the Tx energy efficiency, a novel delay cell exploiting current reuse is used in a ring-oscillator employed as the local oscillator generator scheme. In combination with an edge-combiner power amplifier, the Tx showed a measured energy efficiency of 0.2 nJ=bit and a normalized energy efficiency of 3.1 nJ=bit:mW when operating at output power levels up to -10 dBm and data rates of 3 Mbps

Design and distortion analysis of fully integrated image reject RF CMOS frontends

This thesis presents the design and experimental results of a 7.3GHz notch image reject filter, combined with a 5.8GHz low-noise amplifier (LNA), for integrated heterodyne receiver front-ends. A new image reject filter implementation is proposed. Q-enhancement circuitry for on-chip inductors are used to optimize the depth of image rejection. Experimental results show that more than 62dB of image rejection at 7.3GHz can be obtained in a standard CMOS 0.18mum technology, while operating from a 1.8V supply. The LNA exhibits a gain of 15.8dB and an IIP3 of -5.3dBm while consuming 9mW of power. With maximum image rejection, the LNA-notch combination circuit achieves a 4.1dB noise figure at 5.8GHz. The proposed notch filter alone can operate from a 1V supply voltage. It is shown analytically how circuit stability can be ensured.The implementation of new robust and stable high-Q CMOS image reject filters, which enables the realization of fully integrated heterodyne 5GHz RF receivers is also presented. A cascade of two notch filters with their image reject frequencies slightly offsetted is proposed, in order to obtain a wide image rejection bandwidth, without having to resort to the overhead of automatic tuning circuitry. Thus, power consumption, area, and complexity are significantly reduced. Experimental results show that more than 30d$ of image rejection can be obtained in a standard 0.18mum CMOS technology, over a 400MHz bandwidth centered at 7.4GHz

A 0.29 MM2 12-BIT SEGMENTED CURRENT STEERING DAC WITH DIGITALLY ASSISTED ERROR COMPENSATION GROUPING

Ph.DDOCTOR OF PHILOSOPH

Development and Experimental Analysis of Wireless High Accuracy Ultra-Wideband Localization Systems for Indoor Medical Applications

This dissertation addresses several interesting and relevant problems in the field of wireless technologies applied to medical applications and specifically problems related to ultra-wideband high accuracy localization for use in the operating room. This research is cross disciplinary in nature and fundamentally builds upon microwave engineering, software engineering, systems engineering, and biomedical engineering. A good portion of this work has been published in peer reviewed microwave engineering and biomedical engineering conferences and journals. Wireless technologies in medicine are discussed with focus on ultra-wideband positioning in orthopedic surgical navigation. Characterization of the operating room as a medium for ultra-wideband signal transmission helps define system design requirements. A discussion of the first generation positioning system provides a context for understanding the overall system architecture of the second generation ultra-wideband positioning system outlined in this dissertation. A system-level simulation framework provides a method for rapid prototyping of ultra-wideband positioning systems which takes into account all facets of the system (analog, digital, channel, experimental setup). This provides a robust framework for optimizing overall system design in realistic propagation environments. A practical approach is taken to outline the development of the second generation ultra-wideband positioning system which includes an integrated tag design and real-time dynamic tracking of multiple tags. The tag and receiver designs are outlined as well as receiver-side digital signal processing, system-level design support for multi-tag tracking, and potential error sources observed in dynamic experiments including phase center error, clock jitter and drift, and geometric position dilution of precision. An experimental analysis of the multi-tag positioning system provides insight into overall system performance including the main sources of error. A five base station experiment shows the potential of redundant base stations in improving overall dynamic accuracy. Finally, the system performance in low signal-to-noise ratio and non-line-of-sight environments is analyzed by focusing on receiver-side digitally-implemented ranging algorithms including leading-edge detection and peak detection. These technologies are aimed at use in next-generation medical systems with many applications including surgical navigation, wireless telemetry, medical asset tracking, and in vivo wireless sensors

Radio frequency interference detection and mitigation techniques for navigation and Earth observation

Radio-Frequency Interference (RFI) signals are undesired signals that degrade or disrupt the performance of a wireless receiver. RFI signals can be troublesome for any receiver, but they are especially threatening for applications that use very low power signals. This is the case of applications that rely on the Global Navigation Satellite Systems (GNSS), or passive microwave remote sensing applications such as Microwave Radiometry (MWR) and GNSS-Reflectometry (GNSS-R). In order to solve the problem of RFI, RFI-countermeasures are under development. This PhD thesis is devoted to the design, implementation and test of innovative RFI-countermeasures in the fields of MWR and GNSS. In the part devoted to RFI-countermeasures for MWR applications, first, this PhD thesis completes the development of the MERITXELL instrument. The MERITXELL is a multi-frequency total-power radiometer conceived to be an outstanding platform to perform detection, characterization, and localization of RFI signals at the most common MWR imaging bands up to 92 GHz. Moreover, a novel RFI mitigation technique is proposed for MWR: the Multiresolution Fourier Transform (MFT). An assessment of the performance of the MFT has been carried out by comparison with other time-frequency mitigation techniques. According to the results, the MFT technique is a good trade-off solution among all other techniques since it can mitigate efficiently all kinds of RFI signals under evaluation. In the part devoted to RFI-countermeasures for GNSS and GNSS-R applications, first, a system for RFI detection and localization at GNSS bands is proposed. This system is able to detect RFI signals at the L1 band with a sensitivity of -108 dBm at full-band, and of -135 dBm for continuous wave and chirp-like signals when using the averaged spectrum technique. Besides, the Generalized Spectral Separation Coefficient (GSSC) is proposed as a figure of merit to evaluate the Signal-to-Noise Ratio (SNR) degradation in the Delay-Doppler Maps (DDMs) due to the external RFI effect. Furthermore, the FENIX system has been conceived as an innovative system for RFI detection and mitigation and anti-jamming for GNSS and GNSS-R applications. FENIX uses the MFT blanking as a pre-correlation excision tool to perform the mitigation. In addition, FENIX has been designed to be cross-GNSS compatible and RFI-independent. The principles of operation of the MFT blanking algorithm are assessed and compared with other techniques for GNSS signals. Its performance as a mitigation tool is proven using GNSS-R data samples from a real airborne campaign. After that, the main building blocks of the patented architecture of FENIX have been described. The FENIX architecture has been implemented in three real-time prototypes. Moreover, a simulator named FENIX-Sim allows for testing its performance under different jamming scenarios. The real-time performance of FENIX prototype has been tested using different setups. First, a customized VNA has been built in order to measure the transfer function of FENIX in the presence of several representative RFI/jamming signals. The results show how the power transfer function adapts itself to mitigate the RFI/jamming signal. Moreover, several real-time tests with GNSS receivers have been performed using GPS L1 C/A, GPS L2C, and Galileo E1OS. The results show that FENIX provides an extra resilience against RFI and jamming signals up to 30 dB. Furthermore, FENIX is tested using a real GNSS timing setup. Under nominal conditions, when no RFI/jamming signal is present, a small additional jitter on the order of 2-4 ns is introduced in the system. Besides, a maximum bias of 45 ns has been measured under strong jamming conditions (-30 dBm), which is acceptable for current timing systems requiring accuracy levels of 100 ns. Finally, the design of a backup system for GNSS in tracking applications that require high reliability against RFI and jamming attacks is proposed.Les interferències de radiofreqüència (RFI) són senyals no desitjades que degraden o interrompen el funcionament dels receptors sense fils. Les RFI poden suposar un problema per qualsevol receptor, però són especialment amenaçadores per les a aplicacions que fan servir senyals de molt baixa potència. Aquest és el cas de les aplicacions que depenen dels sistemes mundials de navegació per satèl·lit (GNSS) o de les aplicacions de teledetecció passiva de microones, com la radiometria de microones (MWR) i la reflectometria GNSS (GNSS-R). Per combatre aquest problema, sistemes anti-RFI s'estan desenvolupament actualment. Aquesta tesi doctoral està dedicada al disseny, la implementació i el test de sistemes anti-RFI innovadors en els camps de MWR i GNSS. A la part dedicada als sistemes anti-RFI en MWR, aquesta tesi doctoral completa el desenvolupament de l'instrument MERITXELL. El MERITXELL és un radiòmetre multifreqüència concebut com una plataforma excepcional per la detecció, caracterització i localització de RFI a les bandes de MWR més utilitzades per sota dels 92 GHz. A més a més, es proposa una nova tècnica de mitigació de RFI per MWR: la Transformada de Fourier amb Multiresolució (MFT). El funcionament de la MFT s'ha comparat amb el d'altres tècniques de mitigació en els dominis del temps i la freqüència. D'acord amb els resultats obtinguts, la MFT és una bona solució de compromís entre les altres tècniques, ja que pot mitigar de manera eficient tots els tipus de senyals RFI considerats. A la part dedicada als sistemes anti-RFI en GNSS i GNSS-R, primer es proposa un sistema per a la detecció i localització de RFI a les bandes GNSS. Aquest sistema és capaç de detectar senyals RFI a la banda L1 amb una sensibilitat de -108 dBm a tota la banda, i de -135 dBm per a senyals d'ona contínua i chirp fen un mitjana de l'espectre. A més a més, el Coeficient de Separació Espectral Generalitzada (GSSC) es proposa com una mesura per avaluar la degradació de la relació senyal a soroll (SNR) en els Mapes de Delay-Doppler (DDM) a causa del impacte de les RFI. La major contribució d'aquesta tesi doctoral és el sistema FENIX. FENIX és un sistema innovador de detecció i mitigació de RFI i inhibidors de freqüència per aplicacions GNSS i GNSS-R. FENIX utilitza la MFT per eliminar la interferència abans del procés de correlació amb el codi GNSS independentment del tipus de RFI. L'algoritme de mitigació de FENIX s'ha avaluat i comparat amb altres tècniques i els principals components de la seva arquitectura patentada es descriuen. Finalment, un simulador anomenat FENIX-Sim permet avaluar el seu rendiment en diferents escenaris d'interferència. El funcionament en temps real del prototip FENIX ha estat provat utilitzant diferents mètodes. En primer lloc, s'ha creat un analitzador de xarxes per a mesurar la funció de transferència del FENIX en presència de diverses RFI representatives. Els resultats mostren com la funció de transferència s'adapta per mitigar el senyal interferent. A més a més, s'han realitzat diferents proves en temps real amb receptors GNSS compatibles amb els senyals GPS L1 C/A, GPS L2C i Galileo E1OS. Els resultats mostren que FENIX proporciona una resistència addicional contra les RFI i els senyals dels inhibidors de freqüència de fins a 30 dB. A més a més, FENIX s'ha provat amb un sistema comercial de temporització basat en GNSS. En condicions nominals, sense RFI, FENIX introdueix un petit error addicional de tan sols 2-4 ns. Per contra, el biaix màxim mesurat en condicions d'alta interferència (-30 dBm) és de 45 ns, el qual és acceptable per als sistemes de temporització actuals que requereixen nivells de precisió d'uns 100 ns. Finalment, es proposa el disseny d'un sistema robust de seguiment, complementari als GNSS, per a aplicacions que requereixen alta fiabilitat contra RFI.Postprint (published version