NASA Scientific and Technical Aerospace Reports

20040111137 Lawrence Livermore National Lab., Livermore, CA, Ohio State Univ., Columbus, OH, USA
Asymptotic Technique for the Far Field Pattern of a Dipole in an Infinite Stratified Medium
Rockway, J. T.; Marhefka, R. J.; Champagne, N. J.; Jan. 2001; In English
Report No.(s): DE2003-15005371; UCRL-JC-141930; No Copyright; Avail: National Technical Information Service (NTIS)
Modern antennas especially arrays are being placed in layers of materials on complex environments. This technique
produces aesthetically pleasing structures if necessary, allows for more freedom in structure planning, and can improve
antenna performance. In the past, buried antennas have been studied by numerous authors such as in Reference. Recent work
on this subject uses spectral and/or numerical moment method formulations. For high frequency analysis it is important to find
efficient and accurate methods for design purposes. A rigorous recursive method for plane waves reflection and transmission
coefficients by Richmond has been used in the past for dipoles above multilayer slabs. This solution is modified in this paper
to account for forward and backward traveling rays with appropriate spread factors for a dipole in the media. Extensive
validation for this approximate method shows good agreement with a Method of Moments code. This code is developed at
Lawrence Livermore National Laboratory. The geometry for these comparisons uses a dipole in nontruncated dielectric
multilayer slabs.
NTIS
Antennas; Plane Waves; Spectra
20040111200 Physics and Electronics Lab. TNO, The Hague, Netherlands
FFPAS Evaluation, Phase 1
Boekema, R. B.; vanDorp, P.; January 2004; 61 pp.; In Dutch
Contract(s)/Grant(s): A01/KL/830; TNO Proj. 015.30471
Report No.(s): TD-2003-0055; FEL-03-A116; Copyright; Avail: Other Sources
The Royal Army is using AN/TPQ-36 weapon location radars that have proved their qualities in the fields. The computer
program FFPAS is designed to simulate the performance of this radar in a virtual environment in order to determine the
optimal positioning in the terrain. TNO-FEL is asked to evaluate this commercial available product. This report describes the
first phase of the evaluation of FFPAS. It contains the product inspection of the program, an inventory of the possibilities, and
scientific tests of the functionality. These result in a description of the requirements of a simulator for weaponlocation radars
and are used to describe the shortcomings of FFPAS. The second phase of the evaluation consists of a study on the operational
usability of the program. These two phases will result in an advice for the employment of the program.
Author
Computer Programs; Performance Prediction; Radar Equipment
20040111279 National Telecommunications and Information Administration, Washington, DC
Potential Interference from Broadband Over Power Line (BPL) Systems to Federal Government Radiocommunications
at 1.7-80 MHz, Phase 1 Study, Volume 2
2004; In English
Report No.(s): PB2004-107252; NTIA-04-413-Vol-2; No Copyright; Avail: National Technical Information Service (NTIS)
On April 23, 2003, the Federal Communications Commission (Commission or FCC) adopted a Notice of Inquiry (NOI)
seeking information on potential interference from Broadband over Power Line (BPL) systems and associated changes that
may be needed to accommodate BPL systems in Part 15 of the Commission’s rules. As described in the NOI, ‘access’ BPL
systems transmit Internet and other data at radio frequencies over neighborhood power lines and use electrical outlets in BPL
users’ premises as data ports for computers and other devices. ‘In-house’ BPL systems use indoor wiring for networking
within the user’s premises. In its response to the NOI, the National Telecommunications and Information Administration
(NTIA) described Federal Government usage of the 1.7-80 MHz frequency range, identified associated interference concerns,
and outlined the studies it planned to conduct to address those concerns. NTIA reviewed relevant studies and regulations in
order to help refine the scope and priorities for its studies. NTIA parsed its planned studies into two time phases, first
addressing technical issues of the most immediate importance. As reported herein, Phase 1 defines interference risks to radio
reception in the immediate vicinity of overhead power lines used by ‘access’ BPL systems. It also suggests means for reducing
these risks and identifies techniques for mitigating local interference should it occur.
NTIS
Broadband; Radio Frequencies; Radio Reception; Telecommunication
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