Accession Number : ADD009047
Title : Lossy Matching for Broadbanding Low Profile Small Antennas.
Descriptive Note : Patent Application,
Corporate Author : DEPARTMENT OF THE ARMY WASHINGTON DC
Personal Author(s) : DeSantis,Charles M
Report Date : 23 Nov 1981
Pagination or Media Count : 31
Abstract : A low-profile survivable antenna suitable for military use is described. Despite its small size, which might be one tenth of a wavelength, the antenna has reasonable transmission range for these applications. Very little operator attention is needed in operation, since a special matching circuit within the antenna network enables effective impedance matching, over a 3:1 frequency range, without necessity of switching to different matching circuits over different frequency bands. By including resistive components along with other passive inductive or capacitive elements, the reactance of the single matching circuit is made to effectively compensate the antenna's impedance over the entire frequency range. The impedance of the circuit has a decreasing positive reactance which compensates for the decreasing negative reactance, with frequency, of the antenna. Although the transmission efficiency of the matched antenna network is somewhat diminished by resistive losses, it is still satisfactory, and band switching with this matching circuit is completely eliminated. By including a slender whip screwed into the top, the range can be doubled with no further changes. The matching techniques to be described are most easily realized in the HF through VHF range (1-200 MHz).
Descriptors : *Patent applications, *Broadband antennas, *Impedance matching, Aircraft antennas, Ground vehicle antennas, High frequency, Electrical networks, Very high frequency, Frequency response, Reactance, Matching, Losses
Subject Categories : Electrical and Electronic Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE