Apparatus for and method of measuring local specific absorption range SAR

Abstract

A local SAR measurement device capable of estimating a small-size radio device local SAR on a production line with a high accuracy within a short time. The local SAR measurement device includes a plurality of electromagnetic probes (1) for receiving transmission power from a mobile telephone antenna (12) extending from a mobile telephone main body (11) in Fresnels zone, a combining device for combining the reception powers (2), and a signal processor (3) for estimating a local SAR from the combined reception power. A plurality of electromagnetic probes (1) are used to measure the reception powers of a reference mobile telephone whose local SAR value is known by a precision measurement and a mobile telephone to be measured, so as to estimate the SAR value of the mobile telephone to be measured by utilizing that the SAR value is in proportional relationship with the reception power. Thus, it is possible to measure and evaluate SAR values of a plenty of mobile telephones with a high accuracy in a short time.

Description

technical field [0001] The present invention relates to a Specific Absorption Rate (SAR) measuring device and a method of measuring the Specific Absorption Rate in a small radio device such as a cellular telephone. Background technique [0002] In recent years, from the viewpoint of protecting the body from electromagnetic waves, and with the rapid expansion of the demand for portable radio equipment such as cellular phones, there has been an increasing tendency worldwide to limit the amount of radiation of electromagnetic waves. In particular, when cellular phones are used with their antennas-electromagnetic wave generating sources near the user's head, there is concern about harmful effects on the human body, and therefore, an upper limit value is set for the local absorption rate so that in All countries can constrain and manage it. Besides, in the production process of cellular phones, it is necessary to manage the local absorption rate of the product before shipment, a...

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Problems solved by technology

However, in this configuration, in order to improve the measurement accuracy, the more the measurement positions are, the longer the measurement takes, which is not suitable for application in mass production processes

[0026] In addition, in the proximity electric field detection type apparatus of FIG. 8, and in the proximity magnetic field detection type apparatus described in Japanese Patent No. 2737661 and Japanese Patent No. 2790103, there is such a problem that although usually only one place is measured, the measurement is shortened. time, however, it is difficult to guarantee measurement accuracy due to errors appearing in the measurement results caused by movement of the measurement position or small differences in the radiation pattern of the antenna

[0027] In addition, the electromagnetic wave coupling type device described in JP-A-11-133079 is used to measure the electromagnetic field in a remote field far from the antenna as the object to be measured, and therefore, it is difficult to use this device for SAR near the antenna Measurement

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