Study of the electrical parameters dependences of oblique log-periodic antennas on the geometric structure of their reducing elements

Abstract

Antenna systems are an integral part of any transmitter-receiver device. A broad-band and frequency-independent antenna can be created applying a principle of electrical similarity. Its essence is that the electrical parameters of antennas remain unchanged if, with a decrease or increase in wavelength n times and, accordingly, decrease or increase the linear dimensions of the antenna elements. It is very important to guarantee the constancy of the antenna-radiating element’s parameters in a sufficiently wide frequency range. Log-periodic, biconical and various types of helical antennas satisfy these requirements. Structurally, a log-periodic antenna is a complex structure consisting of a symmetrical two-wire or four-wire collecting line. Radiators of the same type are connected to it in a cross order. The paper presents results obtained on the basis of modeling the electrical parameters of wide-range log-periodic antennas of the decameter range with different shapes of radiating elements in the MMANA-GAL environment. The authors considered methods for constructing periodic structures of flat log-periodic antennas. The interrelation of their structural elements is presented. It determines properties of wide-range operation. The electrical parameters dependences of inclined log-periodic antennas on the structural differences of their radiating elements are investigated. The conditions for the vibrator and frame emitters application are substantiated while maintaining the range properties of the log-periodic structure.