Wideband Microwave Metamaterials Research

 

Overview:

We are currently involved in research on advanced wideband microwave metamaterials.    This new field  has been popularized in the media through numerous reports of emerging metamaterials applications such as  negative refraction, flat lenses, and  optical, thermal and microwave “cloaking” devices.  In essence, metamaterials offer the potential to make objects invisible to heat, light, and microwaves.  However, a fundamental limitation of most metamaterials is that they tend to be inherently narrowband, working over a small range of frequencies.   Thus, a focus of our research is the development of new methods to overcome such bandwidth limitations.  In particular, we are investigating the use of non-Foster integrated circuits, such as negative capacitors and negative inductors, to create wideband metamaterials.

Further Details:

For further details on our project and related research, please see the publications and patents listed below.

Team Members and Contributors:

Drs. Weldon, Adams, and Daneshvar serve as the principal investigators on the project.  Graduate students who have contributed to the project include J. Shehan, J. Covington, V. Kshatri, K. Smith, and K. Miehle.  Undergraduate students who have contributed through their senior design projects include C. Boneque-Santos and A. Tarabichi.

Recent publications:

Recent patents/patents pending:
  • Thomas P. Weldon, Ryan S. Adams, Konrad Miehle, US patent pending 13/766,249, “Wideband Negative-Permittivity Metamaterials and Negative-Permeability Metamaterials  Utilizing Non-Foster Elements,”  Feb. 13, 2013.
  • T. P. Weldon, “Digital discrete-time non-Foster circuits and elements,” International Patent Application No. PCT/US2015/27789, Apr. 27, 2015,  published on WIPO as WO2015164866, Oct. 29, 2015..

Recent Non-Foster Integrated circuits:

Non-Foster integrated circuits are being designed in 0.5 micron CMOS to create negative capacitors and negative inductors.  Below, the image on the left is the layout using Cadence design tools, the image on the right is a photograph of the fabricated integrated circuit chip with wire bonds attached to 40 of the ~150 available bonding pads.

Recent Wideband Microwave Metamaterials:

Recent HFSS simulations of the microwave metamaterial structure below show potential for over two octaves of double-negative metamaterial performance using non-Foster loading of the electric and magnetic structures.

Note: This material is based upon work supported by the National Science Foundation under Grant No. 1101939. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.