Nearly omni‐directional compressed multiband flexible and conformal dipole antenna

Abstract

A physically compressed, multiband dipole antenna on a partially optically transparent Acrylic sheet flexible substrate material is designed. The multi-band operation is achieved by exploiting the higher-order resonating modes. Due to the use of the flexible substrate, and the less metallic footprint of the radiator, the antenna is flexible and conformal with the nearly omnidirectional radiation characteristic in one of the principal plane. With an S11 = −10 dB impedance matching criterion, the antenna has a measured 0.76 to 0.85 GHz, 2.39 to 2.50 GHz, 2.83 to 2.88 GHz, and 6.09 to 6.5 GHz operating bandwidth. It also has a wide −6 dB measured impedance bandwidth from 0.74 to 0.87 GHz, 2.12 to 2.19 GHz, 2.32 to 2.52 GHz, 2.70 to 3.0 GHz, and 5.9 to 6.7 GHz. The specific absorption ratio (SAR) of the conformal antenna has been studied for the collar garment applications. The planar and conformal antennas have been fabricated and investigated for the nearly-omnidirectional radiation pattern. The simulated and measured radiation pattern shows the nearly omnidirectional pattern for a different radius of curvature. The simulated and measured results are in agreement with each other with a few exceptions. The antenna is suitable for the internet of things (IoT), body area networking (BAN), wireless fidelity (Wi-Fi), and smart city applications.