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Group's Philosophy:
Ideas are simple to come by but legwork to convert them into a long-term vision, and then into reality is 90% of the total work.
I have moved to the University of Nebraska-Lincoln, and currently looking for exceptional students with a background in Electromagnetics, RF design, and related areas.
I have moved to the University of Nebraska-Lincoln, and currently looking for exceptional students with a background in Electromagnetics, RF design, and related areas.
Email me at bhardwaj@unl.edu
RESEARCH & TEACHING MISSION
RESEARCH & TEACHING MISSION
Our research mission is to develop circuits and antennas for energy harvesting, wearable / textile electronics and sensors, mm-wave and THz antennas and computational electromagnetics , including automation and EM optimization for RF designs.
Research missions and directions
developing next generation of self-powered and wearable electronic sensors and devices
developing computational tools that are inspired from artificial intelligence for scietific computing
developing computational tools to model terahertz transistors using Multiphysics and multi-scale numerical models.
developing mm-wave and terahertz antennas for RF communication and imaging.
Main Research Thrusts
Slow-wave effects (electron-electromagnetic interactions) at chip-scale.
RF power harvesting and power transfer.
Wearable antennas and RF-ID based medical monitoring / data-collection.
Our second mission is to attract best quality and motivated students to work on latest problems in topics related EM and RF-design.
In News
In News
Graduate Student, Dieff Vital at IMS-2019, Honorable Mention at 3MT Competition
FUNDED ACTIVE PROJECTS AT OUR GROUP
FUNDED ACTIVE PROJECTS AT OUR GROUP
WEARABLE ANTENNAS & ELECTRONICS
Can we wear antennas and electronic-devices for futuristic devices and communication interfaces ? In this effort, we have developed wearable antennas on garments using embroidery of conductive thread which can be used for power harvesting and communication interfaces. Antennas are flexible, low-loss and comfortable to wear. Likewise rectifier circuits are also developed for RF to DC conversion.
Sponsor: NSF ASSIST Center, North Carolina State University (Director: Prof. Veena Misra, NCSU)
Collaborators: Dr. John Volakis, Dr. Doug Werner, Dr. Doug Werner
AUTONOMOUS AUTOMATED DESIGN & COMPUTATIONAL EM
Modern electromagnetic design is a slow and arduous process of iterations of simulations. For complex geometries (including those which are difficult to visualize in 3D sense), design process takes extraordinary effort and time. Within this effort, we solve this issue by automation and automated-optimization algorithms for RF structures. The project involves automated design using scripting and automating HFSS, MATLAB and MATHEMATICA softwares. The project entails automated optimization using machine learning, swarm optimizations and many more.
Sponsor: Air-force Transforming Antenna Center ,(Director: Prof. Stavros Georgakopoulos, FIU)
Collaborators: Dr. Stavros Georgakopoulos
PAST PROJECTS and INTERESTS
PAST PROJECTS and INTERESTS
SUBMM WAVE ANTENNAS for IMAGING AND COMMUNICATION
One of the first circularly polarized horn antennas were realized by a new hexagonal waveguide concept. It was established that hexagonal cross-sectional waveguides are capable of converting TE01 / 10 modes to circularly polarized modes, without using any special features like septum or corrigation. This design was found extremly simple to fabricate and provided 30% 3dB AR bandwidth [1].
A novel measurement method was developed for pattern and gain measurements of CP antennas for mm-wave, sub-mm-wave and THz antennas [2, 3]. Traditionally, these have been extremely difficult measurements owing to high precision of the set-up needed. Here we used reflection based measurements to achieve accurate measurements.
[1] Bhardwaj, Shubhendu, and John L. Volakis. "Hexagonal Waveguide based Circularly-Polarized Horn Antennas for Sub-mm-wave/Terahertz Band." IEEE Transactions on Antennas and Propagation(2018).
[2] S. Bhardwaj, N. K. Nahar and J. L. Volakis, "A Cost-Effective Phaseless Pattern Measurement Method for a CP Antenna in a Submillimeter-Wave Band," in IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 1683-1686, 2017.
[3] S. Bhardwaj, N. K. Nahar, and J. L. Volakis, “Novel phaseless gain characterization for circularly polarized antennas at mm-wave and THz frequencies” IEEE Transactions on Antennas and Propagation, vol. 63, no. 10, pp. 4263–4270, Oct 2015
[2] S. Bhardwaj, N. K. Nahar and J. L. Volakis, "A Cost-Effective Phaseless Pattern Measurement Method for a CP Antenna in a Submillimeter-Wave Band," in IEEE Antennas and Wireless Propagation Letters, vol. 16, pp. 1683-1686, 2017.
[3] S. Bhardwaj, N. K. Nahar, and J. L. Volakis, “Novel phaseless gain characterization for circularly polarized antennas at mm-wave and THz frequencies” IEEE Transactions on Antennas and Propagation, vol. 63, no. 10, pp. 4263–4270, Oct 2015
[1] S. Bhardwaj, F. L. Teixeira and J. L. Volakis, "Fast Modeling of Terahertz Plasma-Wave Devices Using Unconditionally Stable FDTD Methods," in IEEE Journal on Multiscale and Multiphysics Computational Techniques, vol. 3, pp. 29-36, 2018.
[2] S. Bhardwaj, B. Sensale-Rodriguez, H. G. Xing, S. Rajan, and J. L. Volakis. “Resonant tunneling assisted propagation and amplification of plasmons in high electron mobility transistors” Journal of Applied Physics, vol. 119, no. 1, pp.013102, 2016
[3] S. Bhardwaj, N. K. Nahar, S. Rajan, and J. L. Volakis, “Numerical Analysis of Terahertz Emissions from an Ungated HEMT Using Full-Wave Hydrodynamic Model” IEEE Transactions on Electron Devices, vol. 63, no. 3, pp. 990–996, March 2016
[4] S. Bhardwaj, S. Rajan, and J. L. Volakis. “Analysis of plasma-modes of a gated bilayer system in high electron mobility transistors,” in Journal of Applied Physics, vol. 119, no.19, pp. 013102, 2016
[2] S. Bhardwaj, B. Sensale-Rodriguez, H. G. Xing, S. Rajan, and J. L. Volakis. “Resonant tunneling assisted propagation and amplification of plasmons in high electron mobility transistors” Journal of Applied Physics, vol. 119, no. 1, pp.013102, 2016
[3] S. Bhardwaj, N. K. Nahar, S. Rajan, and J. L. Volakis, “Numerical Analysis of Terahertz Emissions from an Ungated HEMT Using Full-Wave Hydrodynamic Model” IEEE Transactions on Electron Devices, vol. 63, no. 3, pp. 990–996, March 2016
[4] S. Bhardwaj, S. Rajan, and J. L. Volakis. “Analysis of plasma-modes of a gated bilayer system in high electron mobility transistors,” in Journal of Applied Physics, vol. 119, no.19, pp. 013102, 2016
Modeling of THz-Transistors using Multiphysics (Electromagnetic + Hydrodynamic) Algorithms
For next generation terahertz devices (catering to 5G, 6G electronics , fast imaging and astronomical observations ), accurate physical modeling of transistors at THz frequency is a challenging task owing to multiple physical phenomenon involved in the modeling. These include electron dynamics and electrodynamic field oscillations in the system. In our past work, we have developed Full-wave-hydrodynamic models to solve this modeling challenge. The developed algorithms utilize ADI-FDTD and iterative ADI-FDTD algorithms for fast solution.
refer to the published work to understand details on this research.
Our Sponsors
Our Sponsors
National Science Foundation
Air Force
Past funding:
DARPA
Air-force Transforming Antenna Center , Director: Stavros Georgakopoulos, FIU
NSF ASSIST Center, North Carolina State University Director: Veena Misra, NCSU
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