Graduate Fellowship Recipients

Project Topic: A thermal actuation/sensing array through efficient and localized heating of magnetic nanoparticles for tumor ablation and neural stimulation.

Project Description:

Localized thermal stress has wide biomedical applications such as tumor ablation and non-invasive neural modulation. However, predominant technologies including dielectric heating and ohmic heating suffer from limited control of spatial extent of the thermal stress which causes damage to surrounding healthy tissues or undesired temperature rise in non-targeted regions. Magnetic heating is an emerging technology utilizing magnetic nanoparticles (MNP) to generate localized thermal stress in response to an external alternating magnetic field. Compared to dielectric heating or ohmic heating, MNP-based magnetic heating offers superior specificity because most of the biological samples are non-magnetic. However, existing MNP-based thermal applicators rely on benchtop magnetic generators at KHz-MHz frequencies, which face two daunting challenges – heating efficiency and spatial resolution. To overcome these challenges, we propose a CMOS microscopic-scale thermal actuation/sensing array based on ferromagnetic resonance of MNP at GHz

microwave frequencies. The proposed system features high energy efficiency, submillimeter spatial resolution, thermal regulation, reconfigurable frequency and magnetic field strength, and a scalable actuation/sensing area, which would be widely applicable in biomedical and clinical applications that require highly localized thermal stress with a cellular-level resolution.

Project Topic: Radiofrequency coils based on high permittivity materials with low losses and/or metamaterials for improved sensitivity MRI.

Project Description: 

Magnetic resonance imaging (MRI) today is a promising tool for medical imaging, due to the high information content and accuracy of data acquisition. At the same time, MRI is a non-invasive and relatively safe method of medical diagnostics for patients’ health. Currently, human MR examinations are becoming highly specialized with a pre-defined and often relatively small target in the body. Conventionally, clinical MR equipment is designed to be universal that compromises its efficiency for small targets. It makes it difficult to diagnose and prescribe treatment for radiologists.

The project is focused on the first application of an artificial-dielectric in a volume coil design for the lower extremities of a person, which operate on two nuclei (31P and 1H), which gives a unique opportunity to study metabolic and microvascular functions in skeletal muscle tissue using measurements of phosphorus and hydrogen protons. The artificial-dielectric resonator operates as a passive wireless structure which is electromagnetically coupled with the body transmit coil on a commercial 3 Tesla clinical MRI system.

The design and prototype was developed of a wireless RF dual-frequencies coil that significantly increase the signal-to-noise ratio (SNR) and image resolution at the same magnetic field strength, as well as reduce scan time at the same image quality.

Project topic: Investigating and proposing novel approaches in exploiting ferrite nonreciprocity to demonstrate a high-power full-duplex transceiver for 5G and future wireless systems.

Project Description: Requiring an ultra-high isolation between Tx and Rx channels at the same frequency and the same time, a full duplex transceiver has become a game changer concept that demands novel insights into redefining the current state-of-the-art in transceivers and microwave components. In our project, we investigate novel fundamental approaches to demonstrate a new class of nonreciprocal ferrite-devices that may find application in full-duplex systems. So far, we have introduced and demonstrated, for the first time, two novel ferrite-devices: ‘Nonreciprocal mode-converting waveguide (NRMCW)’ and ‘concurrent dual-mode circulator’. Exploiting these nonreciprocal devices, this project proposes methodologies to provide an ultra-high in-band isolation between Tx and Rx channels at RF-front-end to establish a full-duplex connection.

Project topic: Fully-printed, 5G-powered wireless sensing modules for perpetual IoT.

Project Description: Our era is witnessing a rapid development in the field of mm-wave and IoT technologies with a projected 50 billion IoT devices to be installed by the end of the decade. Those devices, responsible for sensing and communicating, require the use of batteries that need to be continuously recharged or replaced. Since the number of IoT devices will be massive, it is highly desirable to equip them with harvesting capabilities, and to manufacture them using low-cost and environmentally friendly processes. This work proposes the layer by layer printing of nanomaterials-based Schottky diodes, formed by the ohmic and Schottky contacts responsible for the rectification behavior, necessary for our harvesting application. In addition these unique fully-printed thin-film Schottky diodes will be used to introduce a novel sensing mechanism for fully-passive IoT systems, relying on the functionalization of the printed carbon-nanotubes films and the tunability of the Schottky barriers to enable high sensing capabilities with low-cost fabrication.

Project topic: Nonlinear modeling of GaN HEMTs for RF and microwave applications.

Project Description: The complexity of power amplifier (PA) systems for wireless communications has been escalating because of the increase in signal bandwidth and their required efficiency and linearity. Furthermore, the adoption of higher frequencies and monolithic implementations, has ascribed an essential role on nonlinear models for PA design. Unfortunately, state-of-the-art models of RF power transistors are not sufficiently accurate to design the PA based only on CAD simulations, especially for technologies such as gallium nitride high electron mobility transistors (GaN HEMT), that suffer from deep level traps. This insufficiency of representative and predictive capability of modern models is notably revealed by the nonlinear capacitance models’ internal inconsistency between the charge and energy conservation principles. The objective of this work is thus to discover the fundamental sources of these inconsistencies to then develop new equivalent-circuit compact models of GaN HEMTs that can produce better estimations of real high-frequency measured data, while maintaining high computational efficiency.

Project topic: Fourier domain mode-locked optoelectronic oscillator for multi-band chirped microwave waveform generation.

Project Description: The main objective of the proposed project is to develop a simple and cost-effective multi-band chirped microwave waveform generation scheme for radar applications with high performance. For this purpose, a multi-band Fourier domain mode-locked optoelectronic oscillator (FDML OEO) will be designed. In order to generate multi-band chirped microwave waveforms using FDML OEO, a frequency scanning multi-passband filter with a scanning speed up to tens of kHz will be developed and incorporated into the OEO cavity, which enables the Fourier domain mode locking operation when the scanning period of the multi-passband filter is synchronized with the cavity round-trip time of the OEO loop. The planned work will involve precise design and numerical analysis, and relevant experiments will also be conducted. The project aims to design and demonstrate a FDML OEO-based multi-band chirped microwave waveform generation scheme, with broad bandwidth, reconfigurability, low cost and simple structure.

Project topic: A CMOS microwave broadband adaptive dual-comb spectroscopy system with AI calibration for liquid chemical detection.

Project Description: Self-sustained nondestructive broadband dielectric spectroscopy (MBDS) systems on chip (SoC) for chemicals/biomaterials with μ-level sample volumes have attracted special attention because of a wide range of applications from chemical/biological sensing to agriculture/food safety, and drug development. However, integration of them is challenging for their high frequency operation, small area, low power consumption, required high sensitivity and low volume of the sample. The aim of this research is to investigate and demonstrate a new miniaturized fully integrated, microwave adaptive dual-comb spectroscopy (DCS) system within the 3-10 GHz frequency range in time-domain along with an on-chip system calibration, phase and time correction for highly accurate liquid chemical dielectric permittivity characterization with artificial intelligence.

Project topic: A reconfigurable 60 MHz-30 GHz PLL-less ultra-low-noise frequency synthesizer for 5G and IoT applications.

Project Description: This project presents the first attempt to implement a 30 GHz RF-MEMS oscillator via integrating lithium niobate acoustic resonators and 65 nm CMOS. This millimeter-wave (mmwave) oscillator is envisioned as the heart of a reconfigurable ultra-wide band PLL-less direct frequency synthesizer that is the end goal of this project. As a result of this study, the first voltage-controlled MEMS oscillator based on LiNbO₃ targeting mmwave will be demonstrated. Our resonator is expected to have a Q of 1000 enabling an exceptional CMOS phase noise of -74 and -134 dBc/Hz at 1 kHz and 1 MHz offsets respectively from a 30 GHz carrier while consuming only a dc power of 7mW. The direct RF synthesizer is envisioned to cover an ultra-wide range of frequencies from 60 MHz to 30 GHz via chains of low-power low-noise open loop frequency dividers. A temperature stable solution is also proposed, achieving a temperature stability of sub ppm over a temperature ranging from -20 to 60°C while consuming only micro-watts of dc power.

Project topic: Multiple-mode cavity resonator inspired waveguide circuits using emerging technologies for future communication systems.

Project Description: Nowadays, implementation of multiple-mode resonators (MMRs) in a waveguide structure is a promising solution to dramatically reduce the circuit volume and improve the frequency selectivity. Compared to single-mode resonator (SMR), besides the merits of circuit miniaturization, low-loss, and low-cost, MMRs have an inherent advantage of diverse topologies with better out-of-band signal attenuation, due to the generation of additional transmission zeros (TZs). This project seeks to take advantages of fundamental and high-order modes. By further investigating characteristics of MMRs, a series of innovative circuit components integrated with filtering functions are proposed in a range of application scenarios.  Miniaturization of waveguide circuits is implemented while maintaining the high-Q performance, and highly-integrated multiple-function in a single cavity circuit, is designed with low insertion loss.

Project topic: Advanced optimization based on surrogate modeling and space mapping techniques for computationally efficient modeling and design optimization of coupled signal and power integrity (SI-PI) analysis of high-speed interconnects and power delivery networks.

Project Description: Signal integrity-power integrity (SI-PI) co-analysis becomes essential as modern high-performance computer platforms move towards system-critical conditions. It is crucial to optimize the channel for its best performance and to find the controllable parameter enablers. This project aims to apply techniques based on surrogate modeling and space mapping, to develop an advanced optimization methodology for modeling and design of coupled signal and power integrity analysis of high-speed interconnects and power delivery networks, with high precision and low computational cost.

Project topic: A wideband, high output power amplifier from W-band and above.

Project Description: As the operation frequency of mm-W systems increases thanks to the advanced transistor processes, a wide area of applications in advanced imaging, high-resolution radar, instrumentation, and short-range communication systems are more feasible than ever. Specifically, D-band (110 – 170 GHz) is a local minimum of the atmospheric millimeter-wave absorption, therefore, showing a promising deployment of high-performance systems. One of the most critical of such systems is the power amplifier. The requirements of high efficiency, high output power, and high gain at D-band become incredibly challenging due to the cut-off frequency of the transistor and especially the losses of the passive components. In this work, we aim for a wideband, fully integrated, and high output power of 0.25 Watt covering the entire D band from 110 GHz – 170 GHz using power combining techniques in indium phosphide process.

Project topic: A low-power and low-cost monostatic beamforming radar array based on a novel 2-port transceiver chain using mutually injection-locked oscillators.

Project Description: The objective of this research is to develop a novel, low-power and low-cost 2-port monostatic beamforming radar that features compact size and only one active device in the RF front-end. In this project, although the proposed architecture uses a single antenna for Tx/Rx, no active device or circulator will be needed for Tx/Rx signal isolation. Additionally, mutual injection-locked oscillators will be used to lock the operation frequency and phase along the radar’s array, avoiding the necessity of a dedicated radio frequency PLL system. This system is aimed to enable a new generation of compact and low-cost beamforming radar suitable for massive fabrication, which opens a new gate towards the IoT deployment.

Project topic: Synthesized multi-mode frequency source with ultra-wideband and low phase noise in silicon technology for mmW and sub-THz multi-band application.

Project Description: Millimeter-wave (mmW) and sub-terahertz (sub-THz) bands are promising for high-data-rate communication, imaging radar, detection, and spectroscopy, which require high quality wideband signal. This research aims to achieve ultra-wideband and low phase noise signal source at mmW and sub-THz bands by using multi-mode oscillators and reconfigurable frequency synthesizer architecture. As the outcome of the proposed research plan, the synthesized multi-mode frequency sources for the mmW and sub-THz multi-band operation will be accomplished and verified in silicon technology.

Project topic: Effective control of electromagnetic waves through topological microwave metamaterials.

Project Description: The project is focused on experimental investigation of novel structures for effective control of electromagnetic waves (EMW) – electromagnetic topological insulators (TI) – structures which are insulators in the bulk, but on the surface conduct topologically protected states. These edge modes possess unique properties with the capability to go around the structural defects without back-scattering which makes TI a prospective technology for industry. Moreover, recent advances in physics give rise to a new class of topological systems, called high-order topological insulators (HOTIs) which provide deeper control of EMW through parts of structures, two and more dimensions lower than the system itself.  In spite of active developments of topological photonics the main focus was on studying two-dimensional TI and there is a lack of experimental realization of three-dimensional (3D) TI. The aim of the project is to fill the gap and realize experimental designs of 3D TI and HOTIs based on metamaterials in microwaves. The research has a fundamental character and creates a solid foundation for designing novel devices for different low-loss applications.

Project topic: Broadband electrical sensing of nuclear morphology and DNA content in a single live cell.

Project Description: Morphological and structural changes of cell nuclei as well as DNA content are well-known screening, diagnostic and prognostic markers in cancer cytology. Currently, abnormalities in nuclear morphology and DNA content are mostly determined through optical microscopy and flow cytometry, which almost always require cell labeling, and, hence, are label intensive and terminal tests. A critical question will be if alteration of nuclear morphology and DNA content can be sensed without labeling. Therefore, broadband electrical sensing of single biological cells is proposed in this research to answer the critical question. A stochastic multi-scale model will be developed to understand the interaction of electric fields with cell membrane, cytoplasm and nucleus, including variation of the shape, size and location of the nucleus as well as its DNA content. Broadband electrical sensing and signal analysis of single live human cells will be performed to validate the multi-scale model and extract nuclear morphology and DNA content. Such a label-free technique not only will increase the speed and accuracy of cancer diagnosis over label-dependent optical techniques, but also will enable real-time dynamic monitoring of cancer cell nuclei, which will contribute to fundamental understanding of cell development and malignancy progression.

Project topic: Early skin cancer detection: from desktop imaging setup to real-time handheld device.

Project Description: Skin cancer is the most common cancer in the United States and current estimates indicate that one in five Americans will develop skin cancer in their lifetime according to American Academy of Dermatology. Skin cancers diagnosed and treated early enough are highly curable, and for this reason routine skin exams are highly recommended by dermatologists. Nowadays, skin biopsy is widely used to diagnose suspicious lesions principally due to its accuracy. Despite this, there is a compromise between the advantages and the risk of using this diagnosis process since any medical procedure that involves cutting the skin can be painful and conveys the risk of infection or bleeding. For this reason, the cancer diagnosis industry is experiencing a growth in non-invasive diagnosis techniques, and this trend is expected to continue. Ultra-wideband millimeter-wave (mm-wave) biomedical imaging has recently shown a great promise to provide ultra-high-resolution images for early skin cancer diagnosis. The objective of the proposed project is to develop the next generation of the ultra-wideband millimeter-wave skin cancer diagnosis systems. The proposed system will tackle the most significant challenges that have impeded this technology from entering the $5.3-billion diagnostic market for the most common cancer in the United States. A real-time and portable device equipped with custom-designed hardware and software will be developed. This device will be the first portable and affordable biomedical imaging device capable of producing real- time and ultra-high-resolution images. The novel device will allow point-of-care testing with instant availability of results to make immediate and informed decisions about patient care. It will significantly reduce the size and cost and enhance the assessment speed, convenience, and performance of the current desktop mm-wave skin cancer detection system. The device will be tested on 60 patients in tight collaboration with surgeons from Hackensack University Medical Center, NJ, USA. In addition to ex-vivo experiments for benign tissues and different types of skin cancers such as melanoma, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC), the performance of the novel device will be studied in in-vivo scenarios.