| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide portable terminal equipment having an antenna system and capable of improving an SAR and securing satisfactory communication characteristics. SOLUTION: Two dipole antennas 21 and 22 are provided on a PCB of the main body of portable telephone set. Signal power transmitted from a transmitting/receiving circuit part 6 is distributed by a power distributor/ synthesizer 33, the unbalanced/balanced conversion of a transmitting mode is performed by baluns 36 and 37 through phasers 34 and 35 and the power is supplied through a power feeding terminal to the dipole antennas 21 and 22. By suitably controlling phasesϕ1 andϕ2 of respective antenna currents from 0 to 180 deg. by the phasers 34 and 35, electromagnetic fields close to the head of a human body are mutually canceled and decreased so that the SAR can be reduced. Besides, by controlling the power distribution ratio of the power distributor/synthesizer 22 and the phase of the phasers 34 and 35, a radiation pattern and the SAR are optimized so that communication performance can become satisfactory.</p> |
