Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TC1
Session:
Number:3TC1-1
Calibration of Impedance Measurement of a Balanced Antenna Using the S-Parameter Method
Shohei Konya, Takayuki Sasamori, Teruo Tobana, Yoji Isota,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
In recent years, many wireless telecommunication services have spread over the world. It is known that the characteristics of conventional antennas, such as monopole antennas, change considerably when the body of the handset is touched by the hand. This is caused by the variation of the current on the surface of the conducting box used for the handset due to human body influence. To decrease the influence of the human body, a balanced fed antenna is suggested [1]. The input impedance of the balanced antenna is measured conventionally by using a balun that forces opposite currents into each part of the radiation element. Therefore, the measured result of the input impedance of the balanced antenna includes the influence of the balun. However, an S-parameter method is suggested to measure the balanced impedance of the antenna using a jig instead of the balun, and two ports of a vector network analyzer (VNA) [2], [3]. In this paper, three methods, open-correction, short-correction, and open-short-correction are suggested for compensating for the influence of a jig on the measurement by the S-parameter method. The effects of the three methods are examined by comparing them with the calculated result using the moment method for the input impedance of a dipole antenna. In addition, errors that occur because of the length of the jig are removed by making calibrations using a calibration cable that is almost the same length as the jig.