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- All Subjects: RF
- Creators: Kitchen, Jennifer
- Creators: Benkert, Volker
Description
The increase in computing power has simultaneously increased the demand for input/output (I/O) bandwidth. Unfortunately, the speed of I/O and memory interconnects have not kept pace. Thus, processor-based systems are I/O and interconnect limited. The memory aggregated bandwidth is not scaling fast enough to keep up with increasing bandwidth demands. The term "memory wall" has been coined to describe this phenomenon.
A new memory bus concept that has the potential to push double data rate (DDR) memory speed to 30 Gbit/s is presented. We propose to map the conventional DDR bus to a microwave link using a multicarrier frequency division multiplexing scheme. The memory bus is formed using a microwave signal carried within a waveguide. We call this approach multicarrier memory channel architecture (MCMCA). In MCMCA, each memory signal is modulated onto an RF carrier using 64-QAM format or higher. The carriers are then routed using substrate integrated waveguide (SIW) interconnects. At the receiver, the memory signals are demodulated and then delivered to SDRAM devices. We pioneered the usage of SIW as memory channel interconnects and demonstrated that it alleviates the memory bandwidth bottleneck. We demonstrated SIW performance superiority over conventional transmission line in immunity to cross-talk and electromagnetic interference. We developed a methodology based on design of experiment (DOE) and response surface method techniques that optimizes the design of SIW interconnects and minimizes its performance fluctuations under material and manufacturing variations. Along with using SIW, we implemented a multicarrier architecture which enabled the aggregated DDR bandwidth to reach 30 Gbit/s. We developed an end-to-end system model in Simulink and demonstrated the MCMCA performance for ultra-high throughput memory channel.
Experimental characterization of the new channel shows that by using judicious frequency division multiplexing, as few as one SIW interconnect is sufficient to transmit the 64 DDR bits. Overall aggregated bus data rate achieves 240 GBytes/s data transfer with EVM not exceeding 2.26% and phase error of 1.07 degree or less.
A new memory bus concept that has the potential to push double data rate (DDR) memory speed to 30 Gbit/s is presented. We propose to map the conventional DDR bus to a microwave link using a multicarrier frequency division multiplexing scheme. The memory bus is formed using a microwave signal carried within a waveguide. We call this approach multicarrier memory channel architecture (MCMCA). In MCMCA, each memory signal is modulated onto an RF carrier using 64-QAM format or higher. The carriers are then routed using substrate integrated waveguide (SIW) interconnects. At the receiver, the memory signals are demodulated and then delivered to SDRAM devices. We pioneered the usage of SIW as memory channel interconnects and demonstrated that it alleviates the memory bandwidth bottleneck. We demonstrated SIW performance superiority over conventional transmission line in immunity to cross-talk and electromagnetic interference. We developed a methodology based on design of experiment (DOE) and response surface method techniques that optimizes the design of SIW interconnects and minimizes its performance fluctuations under material and manufacturing variations. Along with using SIW, we implemented a multicarrier architecture which enabled the aggregated DDR bandwidth to reach 30 Gbit/s. We developed an end-to-end system model in Simulink and demonstrated the MCMCA performance for ultra-high throughput memory channel.
Experimental characterization of the new channel shows that by using judicious frequency division multiplexing, as few as one SIW interconnect is sufficient to transmit the 64 DDR bits. Overall aggregated bus data rate achieves 240 GBytes/s data transfer with EVM not exceeding 2.26% and phase error of 1.07 degree or less.
ContributorsBensalem, Brahim (Author) / Aberle, James T. (Thesis advisor) / Bakkaloglu, Bertan (Committee member) / Tirkas, Panayiotis A. (Committee member) / Kitchen, Jennifer (Committee member) / Arizona State University (Publisher)
Created2018
Description
The continuing advancement of modulation standards with newer generations of cellular technology, promises ever increasing data rate and bandwidth efficiency. However, these modulation schemes present high peak to average power ratio (PAPR) even after applying crest factor reduction. Being the most power-hungry component in the radio frequency (RF) transmitter, power amplifiers (PA) for infrastructure applications, need to operate efficiently at the presence of these high PAPR signals while maintaining reasonable linearity performance which could be improved by moderate digital pre-distortion (DPD) techniques. This strict requirement of operating efficiently at average power level while being capable of delivering the peak power, made the load modulated PAs such as Doherty PA, Outphasing PA, various Envelope Tracking PAs, Polar transmitters and most recently the load modulated balanced PA, the prime candidates for such application. However, due to its simpler architecture and ability to deliver RF power efficiently with good linearity performance has made Doherty PA (DPA) the most popular solution and has been deployed almost exclusively for wireless infrastructure application all over the world.
Although DPAs has been very successful at amplifying the high PAPR signals, most recent advancements in cellular technology has opted for higher PAPR based signals at wider bandwidth. This lead to increased research and development work to innovate advanced Doherty architectures which are more efficient at back-off (BO) power levels compared to traditional DPAs. In this dissertation, three such advanced Doherty architectures and/or techniques are proposed to achieve high efficiency at further BO power level compared to traditional architecture using symmetrical devices for carrier and peaking PAs. Gallium Nitride (GaN) based high-electron-mobility (HEMT) technology has been used to design and fabricate the DPAs to validate the proposed advanced techniques for higher efficiency with good linearity performance at BO power levels.
Although DPAs has been very successful at amplifying the high PAPR signals, most recent advancements in cellular technology has opted for higher PAPR based signals at wider bandwidth. This lead to increased research and development work to innovate advanced Doherty architectures which are more efficient at back-off (BO) power levels compared to traditional DPAs. In this dissertation, three such advanced Doherty architectures and/or techniques are proposed to achieve high efficiency at further BO power level compared to traditional architecture using symmetrical devices for carrier and peaking PAs. Gallium Nitride (GaN) based high-electron-mobility (HEMT) technology has been used to design and fabricate the DPAs to validate the proposed advanced techniques for higher efficiency with good linearity performance at BO power levels.
ContributorsRuhul Hasin, Muhammad (Author) / Kitchen, Jennifer (Thesis advisor) / Aberle, James T., 1961- (Committee member) / Bakkaloglu, Bertan (Committee member) / Kiaei, Sayfe (Committee member) / Arizona State University (Publisher)
Created2018
Description
ABSTRACT
German history during the 20th century was extremely complex—containing numerous events that can be labelled horrific and traumatic. The horrors and traumas of WWII forced Germans to actively address their country’s National Socialist pasts by taking responsibility for their roles, creating a national memory about the Nazi atrocities and implementing the reparations program, the Wiedergutmachungsabkommen, with the newly formed nation of Israel. The social theorist Theodor Adorno wrote in his 1959 essay “Was bedeutet: Aufarbeitung der Vergangenheit?” about three subtly nuanced terms: Aufarbeitung der Vergangenheit, Verarbeitung der Vergangenheit and Vergangensheitbewältigung, in which he addresses the various ways that Germany was dealing with traumatic events from this National Socialist past. Adorno specifically demanded a constant renegotiation of the past or Verarbeitung der Vergangenheit because it is the only way forward, through which people remember the horrors and atrocities of the past and work towards not allowing those events to occur again.
This thesis applies the theoretical framework set forth by Adorno to explore efforts to engage the DDR and Stasi past after the Fall of the Wall and reunification. Specifically, it examines the concept of Verarbeitung der Vergangenheit and demonstrates how Thomas Brussig’s satirical novel Helden wie wir, and two documentary films Aus Liebe zum Volk and Das Wunder von Leipzig are examples of working upon this DDR and Stasi past. More specifically, the utilization of humor in the novel and the paralanguage modifications in the films provide insight to the feelings and emotions that individuals had about their pasts in the DDR. It is through this expression of emotion and feelings while writing and speaking about the past, which serves as the immediate moment when individuals actively working upon their pasts.
German history during the 20th century was extremely complex—containing numerous events that can be labelled horrific and traumatic. The horrors and traumas of WWII forced Germans to actively address their country’s National Socialist pasts by taking responsibility for their roles, creating a national memory about the Nazi atrocities and implementing the reparations program, the Wiedergutmachungsabkommen, with the newly formed nation of Israel. The social theorist Theodor Adorno wrote in his 1959 essay “Was bedeutet: Aufarbeitung der Vergangenheit?” about three subtly nuanced terms: Aufarbeitung der Vergangenheit, Verarbeitung der Vergangenheit and Vergangensheitbewältigung, in which he addresses the various ways that Germany was dealing with traumatic events from this National Socialist past. Adorno specifically demanded a constant renegotiation of the past or Verarbeitung der Vergangenheit because it is the only way forward, through which people remember the horrors and atrocities of the past and work towards not allowing those events to occur again.
This thesis applies the theoretical framework set forth by Adorno to explore efforts to engage the DDR and Stasi past after the Fall of the Wall and reunification. Specifically, it examines the concept of Verarbeitung der Vergangenheit and demonstrates how Thomas Brussig’s satirical novel Helden wie wir, and two documentary films Aus Liebe zum Volk and Das Wunder von Leipzig are examples of working upon this DDR and Stasi past. More specifically, the utilization of humor in the novel and the paralanguage modifications in the films provide insight to the feelings and emotions that individuals had about their pasts in the DDR. It is through this expression of emotion and feelings while writing and speaking about the past, which serves as the immediate moment when individuals actively working upon their pasts.
ContributorsDietz, Dominik (Author) / Gilfillan, Daniel (Thesis advisor) / Alexander, John (Committee member) / Benkert, Volker (Committee member) / Arizona State University (Publisher)
Created2016
Description
This thesis describes the design process used in the creation of a two stage cellular power amplifier. A background for understanding amplifier linearity, device properties, and ACLR estimation is provided. An outline of the design goals is given with a focus on linearity with high efficiency. The full design is broken into smaller elements which are discussed in detail. The main contribution of this thesis is the description of a novel interstage matching network topology for increasing efficiency. Ultimately the full amplifier design is simulated and compared to the measured results and design goals. It was concluded that the design was successful, and used in a commercially available product.
ContributorsSpivey, Erin (Author) / Aberle, James T., 1961- (Thesis advisor) / Kitchen, Jennifer (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2012
Description
In the sixty-seven years following the end of World War II, West Germany and Japan underwent a remarkable series of economic and social changes that irrevocably altered their respective ways of life. Formerly xenophobic, militaristic and highly socially stratified societies, both emerged from the 20th Century as liberal, prosperous and free. Both made great strides well beyond the expectations of their occupiers, and rebounded from the overwhelming destruction of their national economies within a few short decades. While these changes have yielded dramatic results, the wartime period still looms large in their respective collective memories. Therefore, an ongoing and diverse dialectical process would engage the considerable popular, official, and intellectual energy of their post-war generations. In West Germany, the term Vergangenheitsbewältigung (VGB) emerged to describe a process of coming to terms with the past, while the Japanese chose kako no kokufuku to describe their similar historical sojourns. Although intellectuals of widely varying backgrounds in both nations made great strides toward making Japanese and German citizens cognizant of the roles that their militaries played in gruesome atrocities, popular cinematic productions served to reiterate older, discredited assertions of the fundamental honor and innocence of the average soldier, thereby nurturing a historically revisionist line of reasoning that continues to compete for public attention. All forms of media would play an important role in sustaining this “apologetic narrative,” and cinema, among the most popular and visible of these mediums, was not excluded from this. Indeed, films would play a unique recurring role, like rhetorical time capsules, in offering a sanitized historical image of Japanese and German soldiers that continues to endure in modern times. Nevertheless, even as West Germany and Japan regained their sovereignty and re-examined their pasts with ever greater resolution and insight, their respective film industries continued to “reset” the clock, and accentuated the visibility and relevancy of apologetic forces still in existence within both societies. However, it is important to note that, when speaking of “Germans” and “Japanese,” that they are not meant to be thought of as being uniformly of one mind or another. Rather, the use of these words is meant as convenient shorthand to refer to the dominant forces in Japanese and German civil society at any given time over the course of their respective post- war histories. Furthermore, references to “Germany” during the Cold War period are to be understood to mean the Federal Republic of Germany, rather than their socialist counterpart, the German Democratic Republic, a nation that undertook its own coming to terms with the past in an entirely distinct fashion.
ContributorsPiscopo, Michael (Author) / Benkert, Volker (Thesis director) / Moore, Aaron (Committee member) / Machander, Sina (Committee member) / Barrett, The Honors College (Contributor) / College of Liberal Arts and Sciences (Contributor)
Created2012-12
Description
The world has seen a revolution in cellular communication with the advent of 5G, which enables gigabits per second data speed with low latency, massive capacity, and increased availability. Complex modulated signals are used in these moderncommunication systems to achieve high spectral efficiency, and these signals exhibit high peak to average power ratios (PAPR). Design of cellular infrastructure hardware to support these complex signals therefore becomes challenging, as the transmitter’s radio frequency power amplifier (RF PA) needs to remain highly efficient at both peak and backed off power conditions. Additionally, these PAs should exhibit high linearity and support continually increasing bandwidths. Many advanced PA configurations exhibit high efficiency for processing legacy communications signals. Some of the most popular architectures are Envelope Elimination and Restoration (EER), Envelope Tracking (ET), Linear Amplification using Non-linear Component (LINC), Doherty Power Amplifiers (DPA), and Polar Transmitters. Among these techniques,
the DPA is the most widely used architecture for base-station applications because of its simple configuration and ability to be linearized using simple digital pre-distortion (DPD) algorithms. To support the cellular infrastructure needs of 5G and beyond, RF PAs, specifically DPA architectures, must be further enhanced to support broader bandwidths as well as smaller form-factors with higher levels of integration. The following four novel works are presented in this dissertation to support RF PA requirements for future cellular infrastructure:
1. A mathematical analysis to analyze the effects of non-linear parasitic capacitance (Cds) on the operation of continuous class-F (CCF) mode power amplifiers and identify their optimum operating range for high power and efficiency.
2. A methodology to incorporate a class-J harmonic trapping network inside the PA package by considering the effect of non-linear Cds, thus reducing the DPA footprint while achieving high RF performance.
3. A novel method of synthesizing the DPA’s output combining network (OCN) to realize an integrated two-stage integrated LDMOS asymmetric DPA.
4. A novel extended back-off efficiency range DPA architecture that engineers the mutual interaction between combining load and peaking off-state impedance. The theory and architecture are verified through a GaN-based DPA design.
ContributorsAhmed, Maruf Newaz (Author) / Kitchen, Jennifer (Thesis advisor) / Aberle, James (Committee member) / Bakkaloglu, Bertan (Committee member) / Ozev, Sule (Committee member) / Arizona State University (Publisher)
Created2022