U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Christopher L. Holloway (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 101 - 125 of 213

Effective Material Property Extraction Of a Metamaterial by Taking Boundary Effects into Account At TE/TM Polarized Incidence

September 22, 2011
Author(s)
Sung Kim, Christopher L. Holloway, James R. Baker-Jarvis, Edward Kuester, Kendra L. Kimberly
In this paper, we present the extraction for effective material parameters for a metamaterial from TE or TM waveguide measurements with generalized sheet transition conditions (GSTCs) used to provide electric and magnetic surface susceptibilities that

Simulation of a MIMO System in a Reverberation Chamber

August 15, 2011
Author(s)
Helge Fielitz, Kate Remley, Christopher L. Holloway
We present a general method to test MIMO antenna setups and algorithms in a reverberation chamber. Our test set-up enables measurement of data throughput using standard laboratory instruments. Using this test set up, effects of antenna setups and/or post

Static and Dynamic Propagation-Channel Impairments in Reverberation Chambers

August 15, 2011
Author(s)
Catherine A. Remley, Sander Floris, Christopher L. Holloway, Scott Prather
We study the separate and combined effects of static and dynamic multipath channels created in a reverberation chamber on bit-error-rate measurements of digitally modulated signals. We demonstrate measurement methods to identify individually both static

Measurement of Shielding Effectiveness of Electrically-Small Enclosures

August 13, 2011
Author(s)
Christopher L. Holloway, Colton R. Dunlap, John M. Ladbury, Joshua A. Gordon, Jason B. Coder, Galen H. Koepke
In the following we propose a technique for determining the shielding effectiveness (SE) an electrically small enclosure. In particular, we use this technique to explore the shielding characteristics of a rectangular box used to shield a satellite based

Radio Frequency Measurements to Support Public Safety Wireless Communications in Large Buildings and Structures

June 13, 2011
Author(s)
William F. Young, Catherine A. Remley, Christopher L. Holloway, Galen H. Koepke, Dennis G. Camell, John M. Ladbury
The public safety community requires dependable wireless communications in buildings that often disrupt the radio frequency propagation due to the construction material, architectural features, or large physical dimensions. Here we introduce measurements

Boundary Effects on the Determination of the Effective Parameters of a Metamaterial from Normal Incidence Reflection and Transmission

June 1, 2011
Author(s)
Sung Kim, Edward E. Kuester, Christopher L. Holloway, James R. Baker-Jarvis, Aaron D. Scher
This paper presents a method for the determination of the effective electromagnetic parameters of a metamaterial, taking boundary effects at the interfaces between a conventional material and metamaterial into account. In the technique presented here

Fluid interactions with metafilm/metasurfaces for tuning, sensing, and microwave assisted chemical processes

May 25, 2011
Author(s)
Joshua A. Gordon, Christopher L. Holloway, James C. Booth, James R. Baker-Jarvis, David R. Novotny, Sung Kim, Yu Y. Wang
In this paper we demonstrate tunability of a metafilm, which is the two-dimensional equivalent of a metamaterial, also referred to as a metasurface, by changing the permittivity in a micro-fluidic channel that interacts with the metafilm. Numerical

Measurements and Models for the Wireless Channel in a Ground-Based Urban Setting in Two Public Safety Frequency Bands

January 20, 2011
Author(s)
William F. Young, Catherine A. Remley, David W. Matolak, Qian Zhang, Christopher L. Holloway, Chriss A. Grosvenor, Camillo A. Gentile, Galen H. Koepke, Qiong Wu
We report on measured peer-to-peer (ground-based) wireless channel characteristics for an urban environment in two public safety frequency bands. Results are based upon measurements taken in Denver in June 2009. The public safety bands we investigated are

A Channel Propagation Model for the 700 MHz Band

September 1, 2010
Author(s)
Camillo A. Gentile, Nada T. Golmie, Catherine A. Remley, Christopher L. Holloway, William F. Young
Conversion from analog television in the United States combined with the appeal for broadband public safety communications is generating a lot of interest in the so-called 700 MHz band between 698-806 MHz. To our knowledge, no channel propagation model for

Examining the True Effectiveness of Loading a Reverberation Chamber

July 29, 2010
Author(s)
Jason Coder, John M. Ladbury, Christopher L. Holloway, Kate Remley
In this paper we explore how placing the same amount of absorber in different locations within a reverberation chamber can have different loading effects. This difference can have a significant impact on measurement reproducibility, both for measurements

Quantum-Based SI Traceable Electric-Field Probe

July 25, 2010
Author(s)
Joshua A. Gordon, Christopher L. Holloway, Steven R. Jefferts, Thomas P. Heavner
We are presently investigating the feasibility of developing a technique that will allow direct traceable microwave electric field (E-field) measurements. The new approach is based on atomic rf-resonance spectroscopy, where an applied electrical field

Bit Error Rate Measurements in Reverberation Chambers using a VSA

June 21, 2010
Author(s)
Catherine A. Remley, Sander Floris, Christopher L. Holloway
We discuss practical measurement implementation issues regarding the use of a vector signal analyzer for making bit-error-rate measurements in reverberation chambers. These issues include synchronizing the transmitted and received signals in spite of time

Reverberation-Chamber Test Environment for Outdoor Urban Wireless Propagation Studies

June 21, 2010
Author(s)
Helge Fielitz, Kate Remley, Christopher L. Holloway, Qian Zhang, Qiong Wu, David W. Matolak
We introduce a test environment to replicate the well-known clustering of reflections in power delay profiles from urban wireless propagation environments that exhibit late-time delays and reflections. The test set-up combines discrete reflections

Parametric Study on the use of Reverberation Chambers for Repeatable/Controllable Wireless Testing: Application to BER Measurements

April 12, 2010
Author(s)
Christopher L. Holloway, E Genender, Catherine A. Remley, John M. Ladbury, Galen H. Koepke
We illustrate use of the reverberation chamber to simulate different wireless propagation environments including effects such as narrowband or frequency-selective fading and Doppler spread. These effects have a strong impact on the quality of the wireless

Radio Wave Propagation Into Large Building Structures, Part 2: Characterization of Multipath

April 2, 2010
Author(s)
Catherine A. Remley, Galen H. Koepke, Christopher L. Holloway, Chriss A. Grosvenor, Dennis G. Camell, John M. Ladbury, Robert T. Johnk, William F. Young
We report on measurements that characterize multipath conditions that affect broadband wireless communications in building penetration scenarios. Measurements carried out in various large structures quantify both radio-signal attenuation and frequency

Experimental Verification of Z Antennas at UHF Frequencies

December 8, 2009
Author(s)
Christopher L. Holloway, Richard Ziolkowski, Peng Jin, J. A. Nielsen, M. H. Tanielian
Both 300 MHz and 570 MHz versions of the electrically small coaxially-fed Z antenna were designed and tested. These two cases demonstrate the ability to change the resonance frequency of the Z antenna by changing the value of its lumped element inductor