Electromagnetic human phantoms for the purpose of antenna design

Abstract

To determine the effective performance of handheld cellular radio antenna, it is essential to evaluate the electromagnetic (EM) interaction between the antenna and the human body. EM evaluation using the real human bodies has drawbacks such as poor repeatability and traceability. This is because the different ways of holding the terminal give a variety of geometric relationship between the terminal and the human head and hand. To develop antennas that are less affected by the human body, the mechanisms for the variations in the characteristics with respect to the antenna structure, caused by absorption in each region of the human body, must be considered. However, measurements made with the respective parts of real human bodies are difficult. Thus, human phantoms are widely used in the various fields of antenna engineering to solve these problems. In realizing human phantoms for the purpose of antenna design, there are two points that have to be considered; (1) What kind of antenna to be estimated? (2) What kind of characteristic to be measured? This paper presents recent status and some technological issues for the development of human phantoms used for antenna designs from the above-mentioned two perspectives. Furthermore, as a new trend of phantom applications towards future wireless radios, MIMO over-the-air testing (MIMO-OTA) using a phantom and an arm-waving dynamic phantom for the assessment of body area network (BAN) systems are briefly introduced.