Antenna gain measurement of hand held terminal at 900 MHz

摘要

For the design of a hand-held terminal antenna, it is necessary to measure radiation efficiency affected by a human carrier. It is difficult to obtain a theoretical analysis for the gain reduction of a hand held terminal located near a human body, especially for different carrier effect. In this paper, we present the antenna gain measurement using the random field measurement method and the measurement system by antenna switching technique. At first, we measure the antenna gain for different sized terminal boxes under indoor/outdoor environments. From these measurement, we show that the indoor environment has almost the same characteristics of cross-polarization level with the outdoor environment. We also show that a small sized terminal box has the highest radiation efficiency. Considering these results, the measurements are carried out under indoor environment with a small terminal box for 30 different human carriers. The average antenna gain is -8.9 dBd with the deviation of /spl plusmn/3 dB for a quarter wavelength whip antenna on a hand held terminal.