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Spectrum Engineering Reports

NOTE: These reports are available either on-line in PDF (portable document) format or only as hard-copy. If you would like a copy of a report that is not available electronically, please make note of the document number and submit your request to:

NTIA Office of Spectrum Management
System Engineering and Analysis Division
Tel. (202) 482-2608
Fax (202) 482-4595

Improved Estimation of the Third-Order Harmonic Emissions of Land Mobile Radio Base Stations

Report ID
NTIA Technical Report TR-11-481
September 01, 2011
Eric D. Nelson and Nicholas DeMinco

Abstract: NTIA/ITS has developed an improved electromagnetic compatibility (EMC) analysis method that can be applied to more accurately model real scenarios for evaluating interference. The methodology described in this report can be used to conduct EMC analyses for base stations that use a variety of antennas. The model can be used to determine the received power in the proximity of the base station at both the fundamental and harmonic frequencies. It uses accurate radio-wave propagation models and antenna models.

A Prototype Antenna for Total RF Field Measurement

Report ID
NTIA Technical Report TR-12-483
October 03, 2011
J. Wayde Allen

Abstract: The total radio frequency (RF) field strength is the sum of all signals incident at a given location. These signals can originate from many directions and have various polarizations. This complicates the measurement of the total RF field since commonly used antennas (dipoles, whips, etc.) respond to signals coming from a specific direction and with a specific polarization. This paper describes a prototype antenna constructed from three crossed dipole elements.

Free-Field Measurements of the Electrical Properties of Soil Using the Surface Wave Propagation Between Two Monopole Antennas

Report ID
NTIA Technical Report TR-12-484
January 02, 2012
Nicholas DeMinco, Robert T. Johnk, Paul McKenna, Chriss A. Hammerschmidt, J. Wayde Allen

Abstract: This report describes one of three free-field radio frequency (RF) measurement systems that are currently being developed by engineers at the Institute for Telecommunication Sciences (NTIA/ITS). The objective is to provide estimates of the electrical properties of the ground (permittivity and conductivity) over which the measurement systems are deployed. This measurement system uses transmission loss measurements between two monopoles placed close to the ground at specific separation distances.

Case Study: Investigation of Interference into 5 GHz Weather Radars from Unlicensed National Information Infrastructure Devices, Part 3

Report ID
NTIA Technical Report TR-12-486
June 01, 2012
John E. Carroll, Geoffrey Sanders, Frank H. Sanders, and Robert L. Sole

Abstract: In early 2009, the Federal Aviation Administration (FAA) became aware of interference to Terminal Doppler Weather Radars (TDWRs) that operate in the 5600–5650 MHz band and provide measurements of gust fronts, windshear, microbursts, and other weather hazards for improved safety of operations in and around airports.

The Rabbit Ears Pulse-Envelope Phenomenon in Off-Fundamental Detection of Pulsed Signals

Report ID
NTIA Technical Report TR-12-487
July 02, 2012
Frank H. Sanders

Abstract: When radiofrequency pulse envelopes are observed away from their fundamental frequency their shapes differ from those at their fundamental frequency. Off-fundamental pulse envelopes tend to exhibit spikes at their rising and falling edges with lower-amplitude energy between the spikes. This phenomenon, called the rabbit ears effect, is described in this NTIA Report. Examples of rabbit ears pulse envelopes are provided in a mathematical simulation and from measurements of off-fundamental pulse envelopes of two models of 5 GHz weather radars.

Relationships Between Measured Power and Measurement Bandwidth for Frequency-Modulated (Chirped) Pulses

Report ID
NTIA Technical Report TR-12-488
August 01, 2012

Abstract: Measured power levels for radio frequency (RF) pulses that are frequency modulated (chirped) vary as a function of the bandwidth in which the measurement is performed; if chirped pulses cause RF interference, the power levels of the pulses in victim receivers will likewise vary as a function of receiver bandwidth. This report provides both heuristic and rigorous derivations of the relationships among chirped pulse parameters and the measured peak and average power levels of chirped pulses as a function of measurement bandwidth.

Conducted and Radiated Emissions Measurements of an Ultrawideband Surveillance Radar

Report ID
NTIA Technical Report TR-13-491
November 01, 2012
Robert T. Johnk, Frank H. Sanders, Kristen Davis, Geoffrey A. Sanders, John D. Ewan, Ronald L. Carey, Steven J. Gunderson

Abstract: We provide detailed descriptions of recent measurements conducted by the National Telecommunications and Information Administration Institute for Telecommunication Sciences in Boulder, Colorado. ITS engineers performed a comprehensive series of both conducted and radiated emission measurements of the Shore-Line-intrusion-Monitoring System (SLiMS). The SLiMS system is currently being developed by Time Domain® under the sponsorship of the Naval Facilities Engineering Command.

Intelligibility of the Adaptive Multi-Rate Speech Coder in Emergency-Response Environments

Report ID
NTIA Technical Report TR-13-493
December 03, 2012
David J. Atkinson, Stephen D. Voran, and Andrew A. Catellier

Abstract: This report describes speech intelligibility testing conducted on the Adaptive Multi-Rate (AMR) speech coder in several different environments simulating emergency response conditions and especially fireground conditions. The intelligibility testing protocol was the Modified Rhyme Test (MRT). Conditions included background noises of various types, as well as a mask associated with a self-contained breathing apparatus. Analog FM radio transmission and Project 25 digital radio transmission were also included in the test as reference points.

Intelligibility of Analog FM and Updated P25 Radio Systems in the Presence of Fireground Noise: Test Plan and Results

Report ID
NTIA Technical Report TR-13-495
May 01, 2013
David J. Atkinson, Andrew A. Catellier

Abstract: This report describes a modified rhyme test (MRT) conducted to characterize the behavior of digital and analog communication in the presence of background noise and moderate RF channel degradation. This is done through the use of reference systems to provide a manufacturer-independent perspective on this issue.