Design Of A 20MHz Transimpedance Amplifier With Embedded Low-pass Filter For A Direct Conversion Wireless Receiver

Accelerated growth in wireless communications in recent years has led to the emergence of portable devices that employ several wireless communication standards to provide multiple functionality such as cellular communication, wireless data communication and connectivity, entertainment and navigation, within the same device. Industry drive is towards reduction of the number of radio frequency (RF) front-end receivers required to cater to the various standards/bands within a single device to reduce cost, size and power consumption. The current trend is to use broadband/multi-standard or reconfigurable RF front-ends to cater to two or three standards at a time for cost-effective RF front-end solutions. The direct conversion receiver architecture has become attractive as it offers a full on-chip front-end solution without the need for expensive external components. Passive current-mode mixers are used in these receivers to eliminate mixer flicker noise. The in-band current signals are typically in the micro-amp range after mixer downconversion. Transimpedance amplifiers are used to convert the downconverted current signals to voltage, and they provide amplification in the process. Because of the co-existence of multiple-radios within each device, large blocker currents downconvert close to the channel bandwidth after the mixer. Conventionally, single-pole transimpedance amplifier (TIA) filters are used to provide out-of-band (OOB) signal filtering. This requires high resolution analog-to-digital converters (ADCs) later in the receiver chain for signal processing. Providing higher order filtering before the ADC relaxes its specifications and this reduces the ADC and ADC calibration cost and complexity. Typically, an extra filtering stage is provided in the form of a cascaded filtering block after the single-pole TIA. In this work, higher order filtering is embedded within the TIA in the form of active feedback. In addition to relaxing the ADC specifications, this proposed TIA provides improved large signal linearity such as P1dB compression point. Furthermore, since the extra-circuitry is not in the signal path, in-band flicker noise and linearity are not degraded. The proposed TIA filter has been designed in IBM 90nm technology with a supply voltage of 1.2V. It can tolerate close-in blocker magnitudes of 4.5mA at 60MHz and higher before in-band 1dB compression is reached

Synthesis of acoustic wave filters : ladder and transversal topologies : towards a practical implementation

The meteoric growth of the mobile communication market for the last three decades has been strongly related with the evolution of the electroacoustic (EA) filter technology. With way over 5 billion cell phone users worldwide in 2017 and 5G standard in the horizon, the radiofrequency spectrum is becoming increasingly crowded whereas demand for mobile data has no expected limits in the short to medium term. In this scenario, where a unique filter needs to be designed for each band of operation, requirements for advanced filtering solutions continue to grow as well as the average value of the RF solutions and the RF content per mobile device. RF and microwave devices based on EA resonators such as Bulk Acoustic Wave (BAW) and Surface Acoustic Wave (SAW) filters overcame the limitations of the existent technologies back in the 1980’s thanks to its compatibility with the manufacturing process of standard Silicon Integrated Circuits (Si-IC). Nowadays sophisticated RF Front-End (RFFE) Modules based on System-in-Package (SiP) are the key solution to integrate the increasing number of electronic parts - Power Amplifiers (PAs), Low Noise Amplifiers (LNAs) and switches - that accompanies acoustic filtering devices like filters, duplexers and multiplexers. Even though the level of complexity and accuracy present on the current EA devices is extraordinary, the design procedures for acoustic filters are still based on the optimization of built-in performance parameters from behavior-based compact models of resonators and the success on this duty relies mostly on the expertise of the designers. However due to the stringent technological constrains and the increasing complexity of the RFFE module architectures devoted to satisfy demanding specifications of the current and forthcoming communications standards, the challenging work of the designers is never getting easier. The aim of this work is focused on providing valuable insights that might help to overcome some of the existent limitations in the design of EA filters. Wider bandwidths, prescribed inclusion of external elements or multiplexing features are taken into consideration. On one hand we show a synthesis formulation and an automated procedure to carry out the synthesis for current well-known topologies, i.e. ladder, taking into consideration realistic values and specifications. On the other hand, a synthesis formulation for novel topologies, named here transversal, is provided. Success of this novel topology will certainly help to guarantee the prevalence of EA filters in the future communication standards, along with the extension to other applications with more stringent requirements and different operating frequencies. The first part of the work is devoted to explain the basic theory related to filter synthesis and its applicability to filters based on EA resonators. Subsequent chapters elaborate the theory to explain the procedures followed to obtain both synthesis and their limitations. Finally, a Chapter devoted to study cases shows the results of applying the filter synthesis to real case scenarios.El creixement meteòric del mercat de comunicacions mòbils durant les últimes tres dècades ha estat fortament relacionat amb l'evolució de la tecnologia de filtres electroacústics (EA). Amb més de 5 bilions d'usuaris de telefonia mòbil al món i amb implantació del 5G a l'horitzó, l'ocupació de l'espectre de radioelèctric és cada cop més gran, mentre que la demanda de dades mòbils no para de créixer exponencialment. En aquest escenari, on s'ha de dissenyar un filtre únic per a cada banda d'operacions, continuen creixent els requisits per a solucions de filtratge avançades, així com el valor mitjà de les solucions RF i el contingut de RF per dispositiu mòbil. Els filtres de radi i microones basats en ressonadors EA com Bulk Acoustic Wave (BAW) i Surface Acoustic Wave (SAW) filtren la superació de les limitacions de les tecnologies existents a la dècada de 1980 gràcies a la seva compatibilitat amb el procés de fabricació de circuits integrats de silici estàndard (Si -I C). Actualment, els sofisticats mòduls de front-end RF (RFFE) basats en System-in-Package (SiP) són la solució clau per integrar el nombre creixent de peces electròniques (amplificadors de potència (PA)), amplificadors de baix soroll (LNAs) i interruptors - que acompanya. dispositius de filtratge acústic com filtres, dúplex i multiplexors. Tot i que el nivell de complexitat i precisió presents als dispositius EA actuals és extraordinari, els procediments de disseny dels filtres acústics continuen basant-se en l’optimització de paràmetres de rendiment integrats a partir de models compactes de ressonadors basats en el comportament i l’èxit d’aquest servei es basa. principalment en l’experiència dels dissenyadors. No obstant això, a causa de les estrictes limitacions tecnològiques i la creixent complexitat de les arquitectures del mòdul RFFE dedicades a satisfer les especificacions exigents dels estàndards de comunicació actuals i propers, el treball desafiant dels dissenyadors no és mai fàcil. L'objectiu d'aquest treball està enfocat a proporcionar informació valuoses que puguin ajudar a superar algunes de les limitacions existents en el disseny de filtres EA. Es tenen en compte grans amplades de banda, la inclusió prescrita d’elements externs o les funcions de multiplexació. D’una banda mostrem una formulació de síntesi i un procediment automatitzat per realitzar la síntesi per a topologies conegudes actuals, és a dir, escala, tenint en compte valors i especificacions realistes. D'altra banda, es proporciona una formulació de síntesi per a noves topologies, anomenades aquí transversals. L’èxit d’aquesta nova topologia ajudarà sens dubte a garantir la prevalença de filtres EA en els futurs estàndards de comunicació, així com l’extensió a altres aplicacions amb requisits més estrictes i diferents freqüències de funcionament. La primera part del treball està dedicada a explicar la teoria bàsica relacionada amb la síntesi de filtres i la seva aplicabilitat als filtres basats en ressonadors EA. Capítols posteriors elaboren la teoria per explicar els procediments seguits per obtenir tant la síntesi com les seves limitacions. Finalment, un capítol dedicat a casos d’estudi mostra els resultats de l’aplicació de la síntesi del filtre a escenaris de casos reals.Teoria del Senyal i Comunicacion

Conception et réalisation d'un transmetteur radio fréquence multistandard pour les communications sans fil et la radio-navigation

Les standards de communication cellulaires de deuxième génération, tel que le GSM, offrent les services de transfert de voix et d’autres services de données à faible débit. Le besoin à ajouter des services multimédia avec un très haut débit, dans les communications sans fil, a mené au développement des systèmes dits de troisième ou de quatrième génération tels que l’UMTS et le Wimax. Par ailleurs, les réseaux sans fil locaux et personnels comme le WLAN, le Bluetooth et le Zigbee sont devenus très populaires. De plus, ce formidable développement est arrivé en phase avec la démocratisation (dans les années 2000) des systèmes de radionavigation par satellite donnant aux usagers un outil simple, efficace et bon-marché pour un positionnement fiable et précis. L’union européenne a lancé un nouveau système de positionnement dit Galileo et les américains ont modernisé leur système de navigation par satellite GPS. Le présent travail de recherche est effectué dans le cadre d’une maîtrise en génie électrique. Dans un premier temps, les principes de fonctionnement et les normes des différents systèmes de communication sans fil et de radio navigation à implémenter sont étudiés et les spécifications et les exigences de chaque standard sont établies. Dans un deuxième temps, diverses architectures radiofréquences susceptibles de répondre aux spécifications établies et aux besoins de réaliser des transmetteurs multistandards performant et économiques sont étudiées. Dans un troisième temps, la conception d’un transmetteur radiofréquence qui supporte plusieurs standards de communication sans fil, notamment les standards GSM, UMTS, Bluetooth, Zigbee, IEEE802.11 b/g et Wimax, ainsi que des signaux de radionavigation de type GPS et Galileo, est menée. Le transmetteur conçu est enfin réalisé et testé

Net Neutrality

This book is available as open access through the Bloomsbury Open Access programme and is available on www.bloomsburycollections.com. Chris Marsden maneuvers through the hype articulated by Netwrok Neutrality advocates and opponents. He offers a clear-headed analysis of the high stakes in this debate about the Internet's future, and fearlessly refutes the misinformation and misconceptions that about' Professor Rob Freiden, Penn State University Net Neutrality is a very heated and contested policy principle regarding access for content providers to the Internet end-user, and potential discrimination in that access where the end-user's ISP (or another ISP) blocks that access in part or whole. The suggestion has been that the problem can be resolved by either introducing greater competition, or closely policing conditions for vertically integrated service, such as VOIP. However, that is not the whole story, and ISPs as a whole have incentives to discriminate between content for matters such as network management of spam, to secure and maintain customer experience at current levels, and for economic benefit from new Quality of Service standards. This includes offering a ‘priority lane' on the network for premium content types such as video and voice service. The author considers market developments and policy responses in Europe and the United States, draws conclusions and proposes regulatory recommendations

Net Neutrality

This book is available as open access through the Bloomsbury Open Access programme and is available on www.bloomsburycollections.com. Chris Marsden maneuvers through the hype articulated by Netwrok Neutrality advocates and opponents. He offers a clear-headed analysis of the high stakes in this debate about the Internet's future, and fearlessly refutes the misinformation and misconceptions that about' Professor Rob Freiden, Penn State University Net Neutrality is a very heated and contested policy principle regarding access for content providers to the Internet end-user, and potential discrimination in that access where the end-user's ISP (or another ISP) blocks that access in part or whole. The suggestion has been that the problem can be resolved by either introducing greater competition, or closely policing conditions for vertically integrated service, such as VOIP. However, that is not the whole story, and ISPs as a whole have incentives to discriminate between content for matters such as network management of spam, to secure and maintain customer experience at current levels, and for economic benefit from new Quality of Service standards. This includes offering a ‘priority lane' on the network for premium content types such as video and voice service. The author considers market developments and policy responses in Europe and the United States, draws conclusions and proposes regulatory recommendations

Wide Bandgap Based Devices: Design, Fabrication and Applications, Volume II

Wide bandgap (WBG) semiconductors are becoming a key enabling technology for several strategic fields, including power electronics, illumination, and sensors. This reprint collects the 23 papers covering the full spectrum of the above applications and providing contributions from the on-going research at different levels, from materials to devices and from circuits to systems