Specific Anthropomorphic Mannequin Head Research Articles

Integrated Miniature Multiband Antenna Designed for WWD and SAR Assessment for Human Exposure

The article introduces a new, low-cost, integrated, multiband antenna design intended for wristbands and wearable wireless devices (WWD). With a miniaturized planar square-shape sizing 29 × 29 mm2, the antenna can fit easily inside WWDs. The proposed design covers the most used frequency bands such as LTE2300, ISM2400, LTE2600, WiMAX3500, WiMAX5200, and ISM5800 in which the antenna reaches up to −25 dB and 6.9 dBi in terms of S11 and gain, respectively. To evaluate the exposure amenability of design on human body, we studied the specific absorption rate (SAR) of the design in two main use cases: multilayered human wrist model and a SAM (Specific Anthropomorphic Mannequin) head model. In each use case, the SAR results in different positions for all frequencies are compared to FCC standards.

Dual-Antenna Concept With Complementary Radiation Patterns for Eyewear Applications

A dual-antenna concept to be integrated in a smart eyewear device is presented. The two antennas are printed on FR4 substrate and placed inside an Acrylonitrile butadiene styrene dielectric eyewear frame manufactured using 3-D printing technology. One of the two antennas is a monopole situated at the back of the eyewear with a specifically shaped ground plane underneath. The second antenna is a balanced-fed loop antenna placed in front of the eyewear with an integrated balun circuit. Both antennas are designed to operate in the 2.4 GHz band of the 802.11b/g/n standard. When compared to a reference single monopole antenna usually used in commercial eyewear, higher gain and complementary radiation patterns are obtained in several useful directions using our dual-antenna solution: 1) in front of the eyewear to communicate with a laptop; 2) in the side direction of the eyewear to communicate with a fixed hotspot access point; and 3) in downward direction of the eyewear to communicate with a peripheral smartphone in the pocket of the user. S-parameters and radiation pattern measurements are given with the eyewear placed over a specific anthropomorphic mannequin head phantom to validate the advantages of this novel dual-antenna concept. Specific absorption rate simulation results are presented showing the proposed antennas stay within the authorized limits.

Cavity‐backed on‐body antenna for customised hearing instrument applications

A novel on-body antenna targeted for 2.45 GHz customised in-the-ear hearing instrument applications is designed, implemented, and measured. The antenna is designed to use the maximum volume available in the user's ear canal and to provide isolation from the user's body. The polarisation is primarily normal to the surface of the head to ensure the best on-body path gain. Efficiency and S-parameters from measurements in free space and on a specific anthropomorphic mannequin head endowed with ears are presented.

Ear-to-Ear On-Body Channel Model for Hearing Aid Applications

The deterministic ear-to-ear on-body channel is modeled by the use of a number of elliptically shaped paths. The semi-major axes of the elliptically shaped paths are adjusted such that they trace the outline of the head. The path gain converges when the number of paths is increased, such that the head is modeled more accurately, and the radiation pattern is sampled in more points. The model is able to take the on-body radiation pattern of the antenna, as well as arbitrary head contours into account. The model is validated by the use of measurements and Ansys HFSS simulations on the specific anthropomorphic mannequin (SAM) head. The model is used with a genetic algorithm in order to synthesize a radiation pattern that is optimal for use with the ear-to-ear on-body channel. The radiation pattern is synthesized in terms of the spherical wave expansion coefficients of the hypothetical small antenna. The variation in the ear-to-ear on-body path gain, due to perturbations of the shape of the nominal SAM head, is studied by the use of a Monte Carlo analysis. The analysis revealed that the path gain that is obtained with a single on-body radiation pattern may vary up to 25 dB.

Generation of a head phantom according to the 95th percentile Chinese population data for evaluating the specific absorption rate by wireless communication devices

A Chinese head phantom (CHP) is constructed for evaluating the specific absorption rate (SAR) by the wireless transceivers. The dimensions of the head phantom are within 4 % difference compared with the 95th percentile data from the China's standard. The shell's thickness and the configuration of the pinna are the same as those of the specific anthropomorphic mannequin (SAM). Three computable models for the mobile phones are generated and used in the SAR simulations with the SAM and the CHP. The results show that the simulated SAR from the SAM head is similar. Its morphological reason has been analysed. The authors discuss the conservativeness of the two head phantoms as well. The CHP can be used in the inter-laboratory evaluation for the SAR uncertainty. It can also provide the information for the SAR variability due to physical difference, which will benefit the maintenance and the harmonisation of the standards.

Accurate Simulation of the Radiation Performance of a Mobile Slide Phone in a Hand-Head Position

An accurate simulation of the radiation performance of a commercial CAD-oriented slide mobile phone, taking into account the influence of the SAM (specific anthropomorphic mannequin) head and hand, is presented. The simulation was performed using the commercial software SEMCAD, which is based on the Finite-Difference Time-Domain (FDTD) Method. The radiation effect on the SAM head and hand close to the phone was also investigated. Throughout the numerical simulations, the return loss, the radiation efficiency, and the near-field distribution of the mobile phone could be obtained, and thus the impact on the human body could be estimated. The slide phone was measured under different conditions. Numerical results were compared with the measurement data, and good agreement was obtained.