III-V Nanowire MOSFET High-Frequency Technology Platform

This thesis addresses the main challenges in using III-V nanowireMOSFETs for high-frequency applications by building a III-Vvertical nanowire MOSFET technology library. The initial devicelayout is designed, based on the assessment of the current III-V verticalnanowire MOSFET with state-of-the-art performance. The layout providesan option to scale device dimensions for the purpose of designing varioushigh-frequency circuits. The nanowire MOSFET device is described using1D transport theory, and modeled with a compact virtual source model.Device assessment is performed at high frequencies, where sidewall spaceroverlaps have been identified and mitigated in subsequent design iterations.In the final stage of the design, the device is simulated with fT > 500 GHz,and fmax > 700 GHz.Alongside the III-V vertical nanowire device technology platform, adedicated and adopted RF and mm-wave back-end-of-line (BEOL) hasbeen developed. Investigation into the transmission line parameters revealsa line attenuation of 0.5 dB/mm at 50 GHz, corresponding to state-ofthe-art values in many mm-wave integrated circuit technologies. Severalkey passive components have been characterized and modeled. The deviceinterface module - an interconnect via stack, is one of the prominentcomponents. Additionally, the approach is used to integrate ferroelectricMOS capacitors, in a unique setting where their ferroelectric behavior iscaptured at RF and mm-wave frequencies.Finally, circuits have been designed. A proof-of-concept circuit, designedand fabricated with III-V lateral nanowire MOSFETs and mm-wave BEOL, validates the accuracy of the BEOL models, and the circuit design. Thedevice scaling is shown to be reflected into circuit performance, in aunique device characterization through an amplifier noise-matched inputstage. Furthermore, vertical-nanowire-MOSFET-based circuits have beendesigned with passive feedback components that resonate with the devicegate-drain capacitance. The concept enables for device unilateralizationand gain boosting. The designed low-noise amplifiers have matching pointsindependent on the MOSFET gate length, based on capacitance balancebetween the intrinsic and extrinsic capacitance contributions, in a verticalgeometry. The proposed technology platform offers flexibility in device andcircuit design and provides novel III-V vertical nanowire MOSFET devicesand circuits as a viable option to future wireless communication systems

CHARACTERIZATION AND MODELING OF III-V TRANSISTORS FOR MICROWAVE CIRCUIT DESIGN

New mobile communication technologies have given a boost to innova-tions in electronic for telecommunications and microwave electronics. It’s clear that the increasing request for mobile data availability, as proved by the growth of 69% of mobile data traffic in 2014, poses great challenges to indus-tries and researchers in this field. From this point of view a rapid diffusion of wireless mobile broadband network data standards, like LTE/4G, should be seen, which requests a state-of-the-art transceiver (i.e., transmitter/receiver) electronics. It will be mandato-ry to use higher frequencies, with wider bandwidth and excellent efficiency, to improve battery duration of mobile phones and reduce the energy consump-tion of the network infrastructures (i.e. base stations). Moreover, the microwave electronics is ubiquitous in satellite systems. As an example the GPS-GLONASS systems, developed respectively by United-States and Russian Federation for geo-spatial positioning, now are commonly used as navigation support for planes, ships, trains, automobiles, and even people. Other interesting applications are the earth-observation satellites, like the Italian system COSMO-SkyMed: a constellation of four satellites developed for the observation of the entire planet. These systems are able to produce a detailed image of the earth surface exploiting a microwave synthetic aperture radar, with the possibility to observe an area even by night or with bad weather conditions. Clearly these features are impossible for traditional opti-cal systems. Even if a lot of electronic applications are focused on the system architec-ture, in microwave electronics the single transistor still plays a key role. In-deed, the number of transistors in high-frequency circuits is low and wide ar-eas are occupied by numerous passive elements, required to optimize the sys-tem performance. There is a lot of interest in finding the optimum transistor operating condition for the application of interest, because the high-frequency electron-device technologies are relatively young and often still in develop-ment, so the transistor performance is generally poor. As a matter of fact, transistor characterization plays a very important role: various measurement systems, developed for this purpose, have been pro-posed in literature, with different approaches and application fields. Moreover, a meticulous characterization of the transistor is the basis for the identification of accurate models. These models, allowing to predict the tran-sistor response under very different operating conditions, represent a funda-mental tool for microwave circuit designers. This thesis will resume three years of research in microwave electronics, where I have collaborated in research activities on transistor characterization and modelling oriented to microwave amplifier design. As various kinds of amplifiers (i.e., low-noise amplifier, power amplifier) have been developed, various characterization techniques have been exploited. In the first chapter, after a presentation of the most common large-signal characterization systems, a low-frequency large-signal characterization setup, oriented to transistor low-frequency dispersion analysis and power amplifier design, will be described as well as the development of the control algorithm of the measurement system and its application to the design of a Gallium-Nitride class-F power-amplifier, operating at 2.4 GHz with 5.5 W of output power and 81% efficiency. Another application of the proposed setup for fast-trap characterization in III-V devices is then reported. Successively, an exten-sion of the setup to very low frequencies will be presented. In the second chapter, small-signal characterization techniques will be dealt with, focusing on noise measurement systems and their applications. Af-ter a brief introduction on the most relevant small-signal measurement system (i.e., the vector network analyzer), an innovative formulation will be intro-duced which is useful to analyze the small-signal response of Gallium-Arsenide and Gallium-Nitride transistors at very low frequencies. Successive-ly, the application of neural network to model the low-frequency small signal response of a Gallium-Arsenide HEMT will be investigated. The third and last chapter will deal with the EM-based characterization of Gallium-Nitride transistor parasitic structures and its usage, combined with small-signal and noise measurements, for developing a transistor model ori-ented to low-noise amplifiers design. In particular, the design of a three stages low-noise amplifier with more than 20 dB of gain and less than 1.8 dB of noise figure operating in Ku-band will be described

Controlling Cavity Magnon Polariton Properties in Frequency and Time Domain

The cavity-magnon-polariton (CMP) is the quasi-particle of a hybrid system that connects photonic excitations to magnonic ones. With this connection, the CMP is an ideal candidate to build a bridge between the promising fields of quantum computing and magnonics. However, for the CMP to fulfill its role as an effective interface, a robust control of its underlying physical properties is imperative. Here, we show how the coupling strength can be manipulated within the experiment by a second continuous drive tone applied directly to the magnon system. Furthermore, switching into the time-domain, we demonstrate a coherent control over the different CMP modes based on ns-short pulses to both oscillating systems. At last, frequency fluctuations are investigated with the future goal of improving magnon coherence times

BiCMOS Millimetre-wave low-noise amplifier

Abstract: Please refer to full text to view abstract.D.Phil. (Electrical and Electronic Engineering

A ku-band phemt mmic high power amplifier design

Ankara : The Department of Electrical and Electronics Engineering and The Graduate School of Engineering and Science of Bilkent University, 2014.Thesis (Master's) -- Bilkent University, 2014.Includes bibliographical references leaves 65-67.Power amplifiers are regarded as the one of the most important part of the radar and communication systems. In order to satisfy the system specifications, the power amplifiers must provide high output power and high efficiency at the same time. AlGaAs/InGaAs/GaAs pseudomorphic high electron mobility transistors (PHEMT) provides significant advantages offering high output power and high gain at RF and microwave frequencies. Considering the electrical performance, cost and the reliability issues, pHEMT monolithic microwave integrated circuit (MMIC) high power amplifiers are one of the best alternatives at Ku-band frequencies (12-18 GHz portion of the electromagnetic spectrum in the microwave range of frequencies). In this thesis, a three-stage AlGaAs/InGaAs/GaAs pHEMT MMIC high power amplifier is developed which operates between 16-17.5 GHz. Based on 0.25 µm gate-length pHEMT process, the MMIC is fabricated on 4-mil thick wafer with the size of 5.5 x 5.7 mm2 . Under 8V drain voltage operation, 26.5-24 dB small signal gain, 10-W (40 dBm) continuous-wave mode output power at 3 dB compression with %25-30 drain efficiency is achieved when the base temperature is 85◦C.Değirmenci, AhmetM.S