Microstrip‐fed complementary Yagi–Uda antenna

Abstract

In this study, a microstrip-fed complementary Yagi-Uda antenna backed with milled cavities is presented. This antenna is intended to radiate as near as possible to the end-fire direction while keeping a low profile and small size. The radiator and reflector elements are U-shaped slots while the director is a rectangular slot. These slots are printed on top of a very thin bendable commercial substrate. The radiator is fed by a microstrip line printed on the bottom side of the substrate. A thick metallic plate in which cavities are milled is placed below the substrate and connected by pin wires to the upper metallisation of the substrate. An S-band prototype is designed, fabricated and measured providing an operational bandwidth of 3% around 2.44 GHz, a maximum gain of about 8 dBi is achieved in the main beam which points towards 46°away from the broadside direction. Finally, simulation results of array and different conformal configurations are presented demonstrating the advantages of the microstrip feeding and the thin substrate material. Bending of the antenna along H-plane and E-plane for different curvatures is evaluated.

A drawer‐conformal radio‐frequency identification antenna with vertically polarised quasi‐endfire radiation

“…The designed leaky wave antenna realises the endfire property with its phase constant slightly larger than the wavenumber in free space. There are also several designs with slots that have been reported [14][15][16]. In Ref.…”

Compact dual‐wideband multi‐mode printed quasi‐Yagi antenna with dual‐driven elements

“…It is therefore highly desirable to have the antenna with wide bandwidth to cover the multiple standards. Yagi antennas are an appealing antennas for use in mobile devices, considering their stable gain versus frequency [1,2]. However, for operation at frequencies at the lower part of the ultra-high frequency (UHF) band, the size of a conventional Yagi antenna becomes too large for practical use [3,4].…”

Half‐mode dielectric waveguide antenna fed by a micro‐strip line with air media for endfire radiation

“…Multiple types of antennas have been adopted to realise endfire radiation on a large conducting plane, such as log-periodic antennas [1][2][3], surface wave antennas [4,5], horn antennas [6,7], Yagi antennas [8][9][10][11][12][13][14][15], and leaky-wave antennas [16][17][18][19]. However, for the antennas in [1][2][3][4][5][6][7][8][9][10][11][12][13][14], the lengths of radiating apertures are too short, which results in a low endfire gain. Moreover, the antennas in [1][2][3][4][5] have the problem of non-uniform energy distribution on the radiating aperture, because only part of the radiating aperture is used at a single frequency point.…”

“…The phase constants are not suitable for the endfire radiation in the antennas [6,7], which leads to a sloping-upwards main-beam direction. For the Yagi antennas in [8][9][10][11][12][13][14][15], since the director element couples less energy from the space when it is far away from the driven element, the increase of the director element has a weaker influence on the endfire gain.…”