A Novel Compact Wearable Antenna Design for Ism Band

Abstract

A compact wearable antenna operating at 2.45 GHz with a novel Electromagnetic Band Gap (EBG) structure as a reflector is proposed. The broadband monopole is used as the main radiator of the antenna, and the gradient feeder structure and etched slot on the ground are used to adjust the matching effect of the antenna port. The current path is extended, and the structure is made more compact by slotting the surface of the EBG cell. Then, a 3 × 3 EBG reflector is constructed and loaded to the bottom of the antenna to improve the antenna gain performance and reduces the specific absorptivity (SAR). A three-layer human model (skin-fat-muscle) has been built in High Frequency Structure Simulator (HFSS) to analyse the influence of human tissue on the wearable antenna system. Combined with the practical application background, the radiation performance of the system under bending is also explored. The simulation results show that the application of EBG reflector can increase the antenna gain by about 4.77 dBi and the front-to-back ratio by 17 dB, reduce SAR by more than 95%, and the overall size of the system is only 60.3 × 60.3 × 3.5 mm 3 (0.49λ). The antenna system has the characteristics of simple structure, small size, high gain, and low SAR value, which is of certain reference value for the research on the wearable antenna.

Slotted Monopole Patch Antenna for Microwave-Based Head Imaging Applications

“…(iv) In comparison with reported ranges in previously published work [ 22 , 24 , 27 , 30 , 31 ], the proposed antenna offeres an effective peak gain of over 6.15 dBi and an efficiency of over 90%. Additionally, (v) the maximum measured SAR value for the head model is constrained to be equal to or below 0.1409 W/kg over the entire usable frequency band, which is less than the values reported in the literature [ 24 , 25 , 28 , 31 ]. Along with the ease of its antenna design and use of affordable materials, it can readily be utilized for head microwave imaging.…”

“…(iii) The acquired bandwidth spans 1.3 to 3.7 GHz, which is relatively wider than the reported antennas in the literature [ 10 , 22 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. (iv) In comparison with reported ranges in previously published work [ 22 , 24 , 27 , 30 , 31 ], the proposed antenna offeres an effective peak gain of over 6.15 dBi and an efficiency of over 90%. Additionally, (v) the maximum measured SAR value for the head model is constrained to be equal to or below 0.1409 W/kg over the entire usable frequency band, which is less than the values reported in the literature [ 24 , 25 , 28 , 31 ].…”

“…(ii) Its overall dimensions are 0.32 λ × 0.28 λ × 0.007 λ, where λ is the lower bandwidth 1.3 GHz frequency wavelength. (iii) The acquired bandwidth spans 1.3 to 3.7 GHz, which is relatively wider than the reported antennas in the literature [ 10 , 22 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 ]. (iv) In comparison with reported ranges in previously published work [ 22 , 24 , 27 , 30 , 31 ], the proposed antenna offeres an effective peak gain of over 6.15 dBi and an efficiency of over 90%.…”

A double hollow rectangular‐shaped patch and with the slotted ground plane monopole wideband antenna for microwave head imaging applications

“…The proposed double hollow-rectangular form is novel, and it comprises with a compact printed double hollow-rectangular shape patch structure with slotted ground plane for a wide impedance bandwidth. The comparative study claims that it is possible to consider the antenna in the microwave imaging applications as it performs better than some existing antennas 1,2,19,20,[22][23][24][25]27,28 in accordance of bandwidth, FF, and gain stability over functional frequency ranges along with relatively compact dimensions and sensitivity with head phantom.…”

“…12 Researchers have been developing separate categories of antennae for head image applications is based on image characteristics for microwaves. There are a few deserving references, such as monopoly antenna with high fidelity, 13 EBG-based patch antenna, 14 directional-omnidirectional UWB antenna, [15][16][17][18] modified Vivaldi antenna, 19 several types of 3D antenna, 20,21 flexible antenna, 22,23 printed monopole antenna, 24,25 monopoly textile patch antenna, 26 CPW and metamaterial loaded monopole antenna. 27,28 Tiny antennas, including broadband, limited SAR, strong impedance match, improved gain, better radiation capacity, greater bandwidth, and reliability, are demanding problems in modern microwave head scanning.…”