Low-Profile, Small Circularly Polarized Inverted-L Antenna With Double-Folded Arms

Printed circularly polarized wire antennas with DC grounded stub

“…The data of the DFILA in Ref. 14 show that the radiation pattern in the xz plane (ϕ = 0°) is symmetric along the + z direction. However, the radiation pattern in the yz plane (ϕ = 90°) is not symmetric enough along the + z direction, which has an angle of eight rotation toward the anticlockwise direction.…”

“…Other than having several advantages in manufacturing, the results in this article also show that the performance of the DFILA [14] can be improved, which is mainly in the radiation pattern. Figure 5 shows the radiation pattern of the HP‐DFILA.…”

“…A low profile and miniature small circularly polarized antenna is proposed in 2010 [14]. The antenna, with two double‐folded inverted‐L arms, has good performance and is simple in structure.…”

“…It is also demonstrated that a more symmetrical radiation pattern can be obtained when comparing with the original wire antenna in Ref. 14. Two fabrication methods, which are named the horizontal printed DFILA (HP‐DFILA) and vertical printed DFILA (VP‐DFILA), are studied.…”

Circularly Polarized Low-Profile Antenna for Radiating Parallel to Ground Plane for RFID Reader Applications

“…Some study groups have reported horizontally polarized printed loop antennas in [11,12], and some groups have studied on open-loop antennas generating CP [13,14]. Moreover, an inverted-L CP antenna and a slender CP antenna have been reported in [15,16], respectively. However, the main beam direction is not parallel to the ground, and the bandwidth is not sufficient.…”