Quasi Log-Periodic Microstrip Antenna with closely coupled elements

Abstract

Quasi Log-Periodic Microstrip Antennaa with closely coupled elements Hidekatsu Ozeki, non-member (Nagoya Institute of Technology) Shigeo Hayashi, non-member (Nagoya Institute of Technology) Nobuyoshi Kikuma, non-member (Nagoya Institute of Technology) Naoki Inagaki, member (Nagoya Institute of Technology)This paper proposes a method of constructing a log-periodic microstrip antenna. Log-periodic technique is considered to be useful to improve the characteristics of aa microstrip antenna (MSA) which is narrow band in nature, without preventing the advantage of low-profile and light weight. The radia.iting elements are co-ax fed and arranged on one side of the common feed line behind the ground plane. This way of arrangement necessarily decreases the element spacings, and increases the mutual coupling between elements. The coupling effect has acted to fill up the inactive frequency regions. Larger coupling between elements due to the necessarily dense arrangement gives advantage in obtaining wide-band frequency characteristics. An example of 5 elements case proves that the present method is useful giving gain of 6 to 10 dBi over about 20 %, bandwidth.

Design of log‐periodic dipole array inspired antenna with very wide bandwidth

“…The proposed antenna design is based on the concept of log‐periodic antenna array technique, where an array of radiating elements with narrow bandwidth is arranged in a log‐periodic way to increase the bandwidth [1–4]. In this article, we present a very wide band antenna that is a combination of two individual antenna elements arranged in a log‐periodic way.…”

“…The implementation of log‐periodic principles in microstrip antennas is presented in Refs. 1 and2, the characteristic of microstrip antenna is improved by log‐periodic technique. In Ref.…”

T‐fed for end‐fire pattern of log‐periodic microstrip array

“…Therefore, many researchers try to incorporate Log periodic principles into microstrip antennas for bandwidth enhancement initially and there after gain improvement. [6][7][8][9][10][11][12][13][14][15][16][17][18][19] However in most of the design alternative elements are on either side of the array axis, that is, element placement is asymmetric along the array axis because the array axis does not contain the centre of element as in case of LPDA. Moreover, unlike in LPDA the radiating edges are parallel to array axis in these cases.…”