RAD Optimization

Model

In this joint project an extremely detailed CAD model (1000 parts) of a flip-top phone was provided by the manufacturer. The model consisted of a multi-layer PCB, shielding, display, digital components and dielectric housing parts. The device was simulated in freespace, head only, and head+hand loaded conditions (3 different hand positions), to investigate radiation performance issues.

Simulation

A minimum grid resolution of 0.1 mm was used to resolve the multi-layer PCB and the curvature of the thin helical antenna. Maximum grid resolutions were reduced in the area of the head phantom, where high permittivity occurs. Broadband and harmonic simulations were run to investigate the performance in the PCS band (centered at 1880 MHz).

Results

Significant RF performance parameters including impedance, radiation efficiency and absorption were considered. Freespace results were validated using the DASY4 measurement system. Good to excellent agreement was obtained. This study illustrated the effects that detuning due to loading under real usage conditions can have on the performance of a mobile phone.

For further information related to this study download the publication.