Wireless Electromagnetic Radiation Assessment Based on the Specific Absorption Rate (SAR): A Review Case Study

Employing Electromagnetic Fields (EMFs) in new wireless communication and sensing technologies has substantially increased the level of human exposure to EMF waves. This paper presents a useful insight into the interaction of electromagnetic fields with biological media that is defined by the heat generation due to induced currents and dielectric loss. The Specific Absorption Rate (SAR) defines the heating amount in a biological medium that is irradiated by an electromagnetic field value. The paper reviews the radio frequency hazards due to the SAR based on various safety standards and organisations, including a detailed investigation of previously published work in terms of modelling and measurements. It also summarizes the most common techniques utilised between 1978 and 2021, in terms of the operational frequency spectrum, bandwidth, and SAR values

Design of a PIFA with Parasitic F-element miniaturised antenna assembly for Lower Band Ultra-wideband and IEEE 802.11a applications

In this article, a planar inverted‐FF antenna with suspended rectangular feeding mechanism is presented for lower band ultra‐wideband and IEEE 802.11a wireless local area network applications. By manipulating the optimum strong electromagnetic coupling distance between driven and parasitic F‐shaped radiators on a small ground plane, two closely separate resonances can be merged to form a wide impedance bandwidth of 73.7% (3.0–6.5 GHz) at |S11| < −10 dB. The overall occupied antenna volume is 30 × 15 × 3 mm3 to satisfy the size requirement of modern wireless devices. The impact of the different antenna geometry parameters on the antenna performance is studied. The corresponding measured radiation patterns, gains and group delays are given to fully characterize the performance of this antenn