An Experimental and Computer Modeling Study of Stepped Radius Monopole Antennas
Abstract
This thesis compares the input impedance numerically calculated by MININEC, NEC, and NECGS with experimental results on stepped radius monopole antennas for swept frequencies. This determines the limitation of computer codes and gives guidelines for Yagi and Log Periodic (LP) antenna designs which use Tapered Linear Antenna Elements (TLAE's) NEC and MININEC, thin wire modeling codes, use different Electric Field Integral Equation (EFIE) formulations of the method of moments for the solution of currents. A cylindrical wire cage model is used via NECGS. Four groups of computer models are developed, varying the number of segments from 1 to 70 for 27-31 MHz. Reflection coefficients of seven experimental models are measured at the antenna feed point, and the input impedances are calculated by an auxiliary computer program. The input impedance is then analyzed by comparing the computer simulation results with measured results. Surprisingly, the input impedance of MININEC is closest to experimental results for monopoles which were constructed with ratios of radius-to-wavelength up to 0.0026.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1988
- Accession Number
- ADA207356
Entities
People
- Jae Y. Yim
Organizations
- Naval Postgraduate School