Accession Number : AD0730616

Title :   Investigation of Impedance Loaded Slot Antennas,

Corporate Author : MICHIGAN STATE UNIV EAST LANSING DIV OF ENGINEERING RESEARCH

Personal Author(s) : Hsieh,Tsing-Zone ; Nyquist,Dennis P. ; Chen,Kun-Mu

Report Date : JUL 1971

Pagination or Media Count : 141

Abstract : A simple, flush-mounted antenna consists of a slot cut in a ground plane and excited by a potential maintained between its edges at a point along its axis. The circuit and radiation properties of electrically small slot antennas doubly loaded by lumped impedances connected between their edges are investigated. In the theoretical investigations, integral equations for the electric field distributions excited in the impedance loaded slots by a delta-function current source are formulated and solved numerically. In terms of these slot fields, the input impedances and the radiation fields of the loaded slot antennas are calculated. These analytical results are confirmed qualitatively by those of complementary experimental studies. It is demonstrated that the electrically small slot can be forced into a near antiresonant condition by the selection of an optimum purely reactive loading. A large input resistance is subsequently obtained. This optimum reactance is found to be usually capacitive while the antenna input impedance is inductive. Low loss capacitive loading and tuning impedances can thus be utilized to implement a high efficiency, small antenna. A second optimum reactance loading leads to radiation field patterns which can be highly directive in the case of the rectangular slot or greatly modified for the annular slot radiator. (Author)

Descriptors :   (*SLOT ANTENNAS, ELECTRICAL IMPEDANCE), INTEGRAL EQUATIONS, NUMERICAL ANALYSIS, COMPUTER PROGRAMS

Subject Categories : Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE