A New Structure of Antenna System in a Handset Enhancing Antenna Gain by Passive Loading--The Case for λ/4 Monopole Antenna--

Masanobu HIROSE  Masayasu MIYAKE  

IEICE TRANSACTIONS on Communications   Vol.E77-B   No.7   pp.956-961
Publication Date: 1994/07/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Personal, Indoor and Mobile Radio Communications)
monopole antenna,  portable handset,  passive loading,  conducting body,  pattern control,  method of moments,  

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We propose a new structure of antenna system to enhance the horizontal plane gain and control the antenna pattern, using passive loading. Our proposed structure can be applied to various kinds of antennas on a handset. We discuss the case of a λ/4 monopole antenna on a handset in this paper. In a new structure of λ/4 monopole antenna system, we show that, 1) the increase of the average gain about 5dB in the horizontal plane can be realized by an optimum load, 2) the antenna pattern can be controlled by changing the value of the passive load so as to have some desirable shapes, and 3) the antenna size can be made smaller by about 6% than the one with no loading because the optimum loading makes the resonant frequency lower. These results were confirmed by the calculations using the method of moments for the EFIE and the measurements.