A5059043955- Microwave Engineering and Waveguides
- Radio Frequency Integrated Circuit Design
- Millimeter-Wave Propagation and Modeling
- Antenna Design and Analysis
- Advancements in PLL and VCO Technologies
- Antenna Design and Optimization
- Radar Systems and Signal Processing
- Superconducting and THz Device Technology
- Advanced SAR Imaging Techniques
- Photonic and Optical Devices
- Analog and Mixed-Signal Circuit Design
- Semiconductor Quantum Structures and Devices
- Semiconductor Lasers and Optical Devices
- Low-power high-performance VLSI design
- Electromagnetic Compatibility and Measurements
- Particle Accelerators and Free-Electron Lasers
- Gyrotron and Vacuum Electronics Research
- Electromagnetic Simulation and Numerical Methods
- Particle accelerators and beam dynamics
- Bluetooth and Wireless Communication Technologies
- Energy Harvesting in Wireless Networks
- Advanced Optical Imaging Technologies
- Acoustic Wave Resonator Technologies
- Advanced Optical Sensing Technologies
- Particle Detector Development and Performance
University of Minnesota
2020-2025
Twin Cities Orthopedics
2022-2023
National Yang Ming Chiao Tung University
2022
The University of Texas at Austin
2022
Carnegie Mellon University
2022
Nagoya University
2022
Moscow Institute of Thermal Technology
2022
Texas Instruments (United States)
2022
University of Notre Dame
2022
Cornell University
2009-2022
This paper presents the first reported 28-GHz phased-array IC for 5G communications. Implemented in 130-nm SiGe BiCMOS, includes 32 TRX elements and features concurrent independent beams two polarizations either TX or RX operation. Circuit techniques to enable precise beam steering, orthogonal phase amplitude control at each front end, tapering steering array level are presented. A TX/RX switch design is introduced which minimizes path loss resulting 13.5 dBm/16 dBm Op1dB/Psat per end with...
Next-generation mobile technology (5G) aims to provide an improved experience through higher data-rates, lower latency, and link robustness. Millimeter-wave phased arrays offer a path support multiple users at high data-rates using high-bandwidth directional links between the base station devices. To realize this vision, phased-array-based pico-cell must large number of precisely controlled beams, yet be compact power efficient. These system goals have significant mm-wave radio interface...
This paper explores the use of multi-port patch antennas (MPPA) as configurable radiators in modern wireless systems for beamforming applications. We introduce an analytical design method based on cavity model. approach allows us to identify relationship between input port excitations and resulting radiation pattern. illustrate mm-wave antenna examples practical our proposed achieve both two-dimensional beam scanning multi-beam capabilities with MPPA. The outcomes this are good agreement...
We will introduce a design of analog-to-digital converters (ADCs) based on digital delay lines. Instead voltage comparators, they convert the input into code by lines and are mainly built blocks. This makes it compatible with process scaling. Two structures proposed, tradeoffs in discussed. The effects jitter mismatch also studied. present two 4 bit, 1 GS/s prototypes 0.13 mum 65 nm CMOS processes, which show small area (0.015 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML"...
This work introduces a 2-D phased array architecture that is suitable for high power radiation at mm-Wave and Terahertz frequencies. We address the challenge of signal generation above cut-off frequency transistors by presenting method based on collective performance large number synchronized sources. As theory shows, both locking/tuning beam steering can be independently achieved manipulating local coupling between nearest neighbors. control results in dynamical network insensitive to...
We introduce a novel frequency tuning method for high-power terahertz sources in CMOS. In this technique, multiple core oscillators are coupled to generate, combine, and deliver their harmonic power the output node without using varactors. By exploiting theory of nonlinear dynamics, we control coupling between cores set phase shift frequency. Using method, two VCOs fabricated 65 nm LP bulk CMOS process. The first one has measured 0.76 mW at 290 GHz with 4.5% range second VCO is 0.46 320 2.6%...
Sub-mm-Wave and terahertz frequencies have many applications such as medical imaging, spectroscopy communication systems. CMOS signal generation at this frequency range is a major challenge due to the limited cut-off of transistors their low breakdown voltage. A recent work has demonstrated high power fixed in sub-mm-Wave using harmonic oscillator [1]. However, for most tunable source necessary. In previous works, multipliers are used an alternative above 150GHz [2]. work, first time we...
We present a passive digital-to-phase converter with sub-degree phase precision for phased array frontends. The tuning approach is based on manipulating the electromagnetic properties of an artificially constructed transmission line. By simultaneously controlling dispersion, characteristic impedance, and loss across structure, shifter minimizes imprecisions while ensuring flat amplitude response different settings. chip prototype fabricated in 130nm SiGe BiCMOS process, occupies area 0.18mm...
In traditional phased arrays as the number of rows and columns increases, complexity array connections phase shifters becomes a major obstacle. This challenge is even more detrimental at mm-Wave THz frequencies where conductive loss, undesired couplings, phase/gain mismatch, high power consumption are among many adverse effects such lengthy connections. To address this issue, work presents novel scalable system for signal generation radiation. Figure 14.6.1 shows architecture consisting 2-D...
A delay-line-based analog-to-digital converter for high-speed applications is introduced. The ADC converts the sampled input voltage to a delay that controls propagation velocity of digital pulse. output code generated based on length pulse in fixed time window. effects quantization noise, jitter, and mismatch are discussed. We show because averaging mechanism delay-line, this structure more power efficient presence noise deep sub-micron CMOS. To feasibility approach, 4 bit 1.2 GS/s designed...
Abstract Picosecond-level phase determinism in timing distribution systems is a requirement for future detectors High Energy Physics. FPGA transceivers traditionally used to propagate signals generally do not meet this stringent requirement, suffering from jumps at startup and drifts due temperature variations. While ad hoc solutions have been developed using features measure correct shifts, they remain specific therefore cannot be generalized all types of links. This paper presents study...
Directional communication at millimeter-wave (mmWave) frequencies is one of the key technologies under development towards anticipated deployment fifth generation mobile access (5G). Silicon-based multi-antenna systems are strong candidates for implementation such directional links; however, performance requirements in general significantly more challenging than those posed by mmWave WLAN links demonstrated so far (e.g. 802.11ad). This work presents an overview recent innovations circuit...
This letter presents a systematic study of multiport wire antennas (MPWA) as step toward reconfigurable radiation apertures, an essential component in modern wireless systems. We predict the surface current distribution structure and derive closed-form relation for pattern aperture function its input port excitations. Based on this, we present design procedure optimal selection locations their respective excitations with desired mind. Finally, develop computationally efficient method to...
We present a solid-state tunable terahertz source that exploits the theory of coupled oscillators to simultaneously achieve high output power and frequency tuning. Our proposed structure effectively generates combines harmonics from multiple synchronized in loop configuration. study dynamics system, find stable modes, show how can dynamically select desired coupling mode. Using this method, we fabricated 0.29 0.32 THz sources with peak powers 0.76 0.5 mW both standard 65 nm bulk...
In this letter, we introduce a design methodology to implement generic multi-port aperture that can provide far more flexibility compared regular phased arrays. Using small-scale abstraction of the network develop scalable circuit-level interpretation radiator overcomes need for full-wave and simulation aperture. As proof concept, an 11-port wired antenna prototype with ability adjust its center frequency while synthesizing desired far-field pattern only by modulating excitation phasors...
In this paper we introduce a novel Analog-to-Digital architecture for high speed applications that is compatible with digital CMOS and surpasses the issues traditional voltage conversion techniques. The quantization method based on delay-to-digital concept as means to quantize variable delay line. A 4 bit 1 GS/s ADC mW power consumption designed in 65 nm proposed architecture. new highly scalable technology because of its delay-line-based core, ADCs performance enhances further scaling...
This work presents a mm-wave signal generation method that provides background phase tuning and self-alignment between adjacent sources. technique is based on direct monitoring of the through baseband feedback loop. We present theory concept, provide design methodology, validate proposed with two-element prototype in 65-nm CMOS process. The has chip area 1.3 mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math...
In this paper, we propose a 2-D electrical interferometer as means of high-speed data conversion. The structure is based on wave propagation in LC lattices. We will discuss the principle behind technique, which exploits and medium manipulation order to take advantage different interference patterns. This method quantization passive lattices that can operate at very high frequencies conventional CMOS process. analyze properties design methodology. To show feasibility approach, 20-GS/s 4-bit...
We present a multichip scalable phased array based on nearest-neighbor phase self-alignment. The proposed scheme relies mm-wave interferometric detection and baseband adjustment forming distributed control scheme. introduce the architecture develop proof of concept where chips are fabricated in TSMC 65 nm process. form by implementing chip-to-chip interconnects for with an on-board antenna array. Over-the-air measured patterns produce reliable inter-element values resulting calibration-free...
Abstract We report on the development and performance of a digitally controlled phase delay with step 280 femtoseconds dynamic range 230 picoseconds. Details device design simulations as well comparisons laboratory measurements will be discussed. describe how we have used this ASIC to stabilize digital clock precision less than one picosecond.
This work presents a scalable phased array architecture based on background phase alignment between its nearest neighbors. We implement the proposed interferometric monitoring scheme in multi-chip configuration with chip-to-chip bonding adjacent modules. The prototype $1\times 7$ consists of 7 transmitter chips and 6 control all fabricated TSMC $65\mathrm{n}\mathrm{m}$ CMOS process. die areas two modules are $0.86\mathrm{m}\mathrm{m}^{2}$ $0.41\mathrm{m}\mathrm{m}^{2}$, respectively....