The effects of the handset case, battery, and human head on the performance of a triple-band internal antenna

An internal triple-band antenna fed by a microstrip line is proposed for operation in the PCS (1750-1870 MHz), IMT-2000 (1920-2170 MHz), and Bluetooth (2402-2483.5 MHz) bands. It has the advantages of sufficient impedance bandwidth, easy placement on the substrate, and compact size over most internal antennas. At first, only the antenna itself is designed to satisfy the desired operation, but, in the real situation, its performance is affected by the handset case, battery, or human head. In most cases, it is not uncommon that the antenna is modified to obtain the desired characteristics. Accordingly, the variation of the antenna performance for that case should be investigated. We present advanced physical models for the effects of case, battery and head on the proposed antenna for accurate simulations of real situations. Measured data is compared with computational results to validate the proposed design methods.