S‐shaped planar antenna with 45° tilted bidirectional radiation pattern for motorcycle helmets

Abstract

An S-shaped planar antenna (SPA) with a bidirectional radiation pattern and beam tilt characteristic is proposed to achieve maximum communication distance for helmet applications. The proposed SPA is comprised of an S-shaped radiation strip (consisting of a microstrip meander line and two main arms with two inverted L-shaped parasitic elements) and a rectangular ground plane, where a simplified microstrip power divider is introduced by modifying the feed structure in the center of the SPA, such that the S-shaped radiation strip works in the second resonant mode. The proposed SPA generates a tilted beam in the E-plane with an angle of 45 , which is attributed to the obliquely staggered arms of the antenna at a distance. By introducing inverted L-shaped parasitic elements at the end of the two arms, the directivity of the bidirectional radiation pattern can be further improved, thereby increasing the antenna gain. The working principle is analyzed theoretically, and the effects of the antenna structural parameters on the radiation pattern are also analyzed. The experimental results indicate that the 3:1 VSWR impedance bandwidth is 120 MHz, with a realized peak gain of 1.5 dBi at 2.45 GHz. The proposed antenna is designed for real-world applications, allowing the antenna to be obliquely installed while keeping the peak gain direction horizontal for maximum communication distance.

Antenna Systems in Medical Masks: Applications for 5G FR1 and Wi-Fi 7 Wireless Systems

“…Table 3 is a comparison table between the proposed antenna and other antenna studies. The sizes of the antennas in references [12,[14][15][16][17][18][19][20][21] are larger than that of the antenna system in this paper. Among them, the references [12][13][14][15]19,20] only support two working frequency bands.…”

“…Most of the antenna designs in the literature are simple and common single-stage antennas [12,16,18,19,21]. One of these antennas is designed as a multi-frequency antenna [18,21], but these antennas are not MIMO antenna systems.…”

“…Reference [20] does not support the frequency band of 5G FR1. In addition, all the antennas of [12][13][14][15][16][17][18][19][20][21] are designed on a single material, while Ant. 1 and Ant.…”

“…The wearable devices only use Wi-Fi for data transmission [12][13][14][15][16], or only use 4G/5G frequency bands for data transmission [17]. However, the wearable device users not only use the wearable device indoors but may also move outdoors; • A small number of wearable devices are designed with antennas that include Wi-Fi and 5G communication frequency bands [18] or use Wi-Fi and LTE frequency bands for data transmission [19,20]; other antennas are even designed with three different frequency bands [21].…”

“…However, the wearable device users not only use the wearable device indoors but may also move outdoors; • A small number of wearable devices are designed with antennas that include Wi-Fi and 5G communication frequency bands [18] or use Wi-Fi and LTE frequency bands for data transmission [19,20]; other antennas are even designed with three different frequency bands [21]. However, the design of the antenna is too complicated and the area is too large so that the antenna is not suitable to be installed in the wearable device; • Most of the antennas are flat designs [13][14][15][16][17][18][19][20][21], which cannot be applied to wearable devices with curved-structure designs; • Traditional antenna designs are only applied to a single material [12][13][14][15][16][17][18][19][20][21], while wearable devices are often made of multiple materials.…”