Study HAC Solution For Mobile Phone Antenna

Double driven by the market and technology, mobile communications going to broadband, intelligent, multi-operational is an inevitable trend [1]. Due to the one who has Hearing problem, the electromagnetic interference in the process of calling by phone with hearing aids will make the call become abnormally unclear. HAC is a measure of electromagnetic interference from electromagnetic fields generated by mobile phone antenna for those who wear a hearing aid. This is one of the important indicators for the measurement of mobile phone antenna electromagnetic compatibility. HAC requirements but only gradually emerged in recent years. In some countries, HAC already has mandatory requirements, such as the United States. China also has its own HAC standard, but not mandatory. With the global mobile phone manufacturers export business increased, more and more attentions on the HAC requirements have emerged. Most of the foreign customers take HAC as an important basis for product inspection.This paper first briefly describes the mobile phone antenna normal electrical parameters, which include impedance adapting, bandwidth, radiation efficiency, Total Radiated Power TRP, Total Isotropic sensitivity TIS, far-field radiation pattern, antenna division for near field and far-field, HAC (Hearing Aid Compatibility). Then the electromagnetic compatibility indicators of HAC are studied mainly for the cell phone antenna to work with hearing aids. Furthermore, taking 1900MHz bands(North America) as a study example, the antenna near-field electromagnetic field distribution of the mobile phone mounted Monopole antenna are simulated and the corresponding characteristics of the detection in differences are analyzed with CST Microwave Studio software. Finally, three HAC pre-research solutions are studied and a multi-band antenna base on the pre-study program of HAC solution3 is designed and also optimized to meet ANSI C63.19 HAC standards. To design a kind of antenna that not only satisfies antenna communication performance, but also has good Hearing aid electromagnetic compatibility is an issue that mobile antenna must face to. In this paper, take monopole antenna as the study object, we study the ways to improve the HAC performance in detail when designing single-band and multi-band antennas,. The results may provide references for antenna electromagnetic compatibility design.