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Search Publications by: John Ladbury (Fed)

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Displaying 1 - 25 of 154

Characterizing LTE User Equipment Emissions Under Closed-Loop Power Control

April 6, 2021
Author(s)
Jason Coder, Aric Sanders, Michael R. Frey, Adam Wunderlich, Azizollah Kord, Jolene Splett, Lucas N. Koepke, Daniel Kuester, Duncan McGillivray, John M. Ladbury
This report presents a laboratory-based characterization of Long Term Evolution (LTE) User Equipment (UE) emissions under closed-loop power control, building on our prior work (NIST TN 2069), which assessed the impact of a large number of factors affecting

Characterizing LTE User Equipment Emissions: Factor Screening

September 30, 2019
Author(s)
Jason Coder, Adam Wunderlich, Michael R. Frey, Paul T. Blanchard, Dan Kuester, Azizollah Kord, Max Lees, Aric Sanders, Jolene Splett, Lucas N. Koepke, Rob Horansky, Duncan McGillivray, John M. Ladbury, Jeffrey T. Correia, Venkatesh Ramaswamy, Jerediah Fevold, Shawn Lefebre, Jacob K. Johnson, John Carpenter, Mark Lofquist, Keith Hartley, Melissa Midzor
Characterizations of long-term evolution (LTE) user equipment (UE) emissions are a key ingredient in models of interference between wireless cellular networks and other systems that must use the same radio frequency spectrum. This report presents (i) a

LTE Handset Emissions: Radiation Pattern Measurements Final Test Report

August 16, 2019
Author(s)
Robert D. Horansky, Jason B. Coder, John M. Ladbury
The Defense Information Systems Agency (DISA) Defense Spectrum Organization (DSO) throughthe Spectrum Sharing Test and Development (SSTD) program proposed a National AdvancedSpectrum and Communications Test Network (NASCTN) measurement campaign to

Carbon Nanotube Thin Film Patch Antennas for Wireless Communications

May 24, 2019
Author(s)
E. A. Bengio, Damir Senic, Lauren W. Taylor, Robert J. Headrick, Michael King, Peiyu Chen, Charles A. Little, John M. Ladbury, Chris Long, Christopher L. Holloway, Aydin Babakhani, James Booth, Nate Orloff
Early work on carbon nanotube (CNT) antennas indicated that their performance could not match that of metals such as copper. However, recent improvements in fluid phase CNT processing have yielded macroscopic CNT materials with better alignment and

EMC and Metrology Challenges for 5G and Beyond

December 7, 2018
Author(s)
Perry F. Wilson, Catherine A. Remley, William F. Young, Camillo A. Gentile, John M. Ladbury, Dylan F. Williams
The potential to connect people and devices anywhere and anytime is driving the development and deployment of a multitude of wireless systems. Wireless connectivity is central to advanced communication technologies, the internet of things (IoT), the smart

Measured Emission Spectra of Selected AWS-3 LTE Transmitters

January 16, 2018
Author(s)
Michael R. Frey, Geoffrey Sanders, Jolene Splett, John M. Ladbury, Frank Sanders, Azizollah Kord, Ryan T. Jacobs
Version three of Advanced Wireless Services (AWS-3) radio systems will soon use spectrum that is adjacent to bands currently used by airborne telemetry links at U.S. government test and training ranges (TTRs). It is possible that out-of-band (OoB) and

Equivalent Isotropic Response as a Surrogate for Incident Field Strength

July 9, 2017
Author(s)
Dan Kuester, Duncan McGillivray, William F. Young, John M. Ladbury, Ari Feldman, Adam Wunderlich, Sheryl M. Genco
The strength of a radiated field at some location in free space can be described in terms of the equivalent conducted output from an isotropic probe antenna with a specified reference polarization. This metric has already entered use by various standards

A Radio Frequency Radiation Reverberation Chamber Exposure System for Rodents

March 17, 2017
Author(s)
Perry F. Wilson, John M. Ladbury, Galen H. Koepke, Capstick Myles, Niels Kuster, Sven Kuhn, Veronica Berdinas-Torres, Yijian Gong, David McCormick, James Gauger, Ronald Melnick
In this paper we present the novel design features, their technical implementation, and an evaluation of the radio frequency (RF) exposure systems developed for the National Toxicology Program (NTP) of the National Institute of Environmental Health

Life Time Dosimetric Assessment for Mice and Rats Exposed to Cell Phone Radiation in Reverberation Chambers

March 17, 2017
Author(s)
Perry F. Wilson, John M. Ladbury, Galen H. Koepke, Yijian Gong, Myles Capstick, Keven Kuhn, David L. McCormick, Ronald L. Melnick, Niels Kuster
In this paper, we present a detailed life time dosimetry analysis for individually housed rodents exposed to radio frequency (RF) signals. The unrestrained rodents were exposed in reverberation chambers for 2 years at three whole-body averaged specific

LTE impacts on GPS

February 15, 2017
Author(s)
William F. Young, Ari D. Feldman, Sheryl M. Genco, Azizollah Kord, Daniel G. Kuester, John M. Ladbury, Duncan A. McGillivray, Audrey K. Puls, Andre R. Rosete, Adam J. Wunderlich, Wen-Bin Yang
This report describes the test methodology from “LTE impacts on GPS: Test and Metrology Plan” developed by National Advanced Spectrum and Communications Test Network (NASCTN), and data that are the result of executing the test method. The fundamental goals