Performance of the Monopole Antenna Element for the 96-Element Receiving Array of the High-Frequency, High- Resolution Experimental Site. Volume 2, Appendices

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Abstract:

The theoretical performance of the antenna element for the 96-element receiving array of MITREs High-Frequency, High-Resolution Experimental Site is analyzed. The antenna element consists of a monopole tower with a buried radial- wire ground screen of modest diameter. Each element is connected by a long buried coaxial cable to an associated receiver in one of three electronics shelters within the array. The analysis forms the basis for selecting the final design configuration of the monopole antenna element, its associated ground screen, and the buried feed cable. System internal noise figure and antenna directivity serve as the principal measures of performance The contributions of antenna efficiency, cable mismatch loss, cable attenuation loss, and receiver noise figure to system internal noise figure are treated. The monopole antenna element and an alternative dipole antenna element are modeled and analyzed using the Numerical Electromagnetics Code-Ground Screen NEC-GS version of the NEC method-of-Moments software. NEC-GS, which is particularly well-suited for modeling azimuthally symmetric structures, is used to calculate the antenna input impedance, efficiency, and power gain pattern. The antenna efficiency, cable mismatch loss, and antenna directivity pattern are determined as a function of frequency, earth electrical properties, and antenna elementground- screen geometry. Asymmetric radiation pattern effects caused by a long, buried or unburied, coaxial feed cable, and by a nearby electronics shelter, are also evaluated. This is accomplished by using NEC software versions NEC-31 and NEC-3 to model the monopole with ground screen in the presence of a jacketed feed cable and a shelter, respectively.

Author(s):
Lagace, R. L.
Author Organization(s):
MITRE CORP BEDFORD MA
Pagination:
0154

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release
Distribution Statement:
Approved For Public Release; Distribution Is Unlimited.

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
MTR-11291-VOL-2
Monitor Series:
XJ
 Subject Terms
Joint Capability Areas:
JCA_6.1.1_Wired Transmission; JCA_6_Net Centric; JCA_6.1_Information Transport; JCA_4.4.1_Food Service; JCA_4.4_Logistics Services; JCA_8_Building Partnerships
Communities of Interest:
Advanced Electronics
Descriptor(s):
*ELECTRICAL PROPERTIES, *SOILS, *RECEIVERS, *DIPOLE ANTENNAS, *MONOPOLE ANTENNAS, *ELECTRICAL RESISTANCE, FREQUENCY, INPUT, DIAMETERS, RADIATION, HIGH FREQUENCY, MODELS, CONFIGURATIONS, METHOD OF MOMENTS, NOISE, POWER, ATTENUATION, PATTERNS, CLAY, DIPOLES, ANTENNAS, GAIN, REACTANCE, POWER GAIN, COAXIAL CABLES, IMPEDANCE, MOISTURE CONTENT, WIRE, CABLES, ARRAYS, EFFICIENCY, SAND, HIGH RESOLUTION
Field(s)/Group(s):
Soil Mechanics, Electrical and Electronic Equipment, Electricity and Magnetism
Keyword(s):
ANTENNA ELEMENT, NUMERICAL ELECTROMAGNETICS CODE GROUND SCREEN(NEC GS)
Report Date:
1991 Dec 01