Showing papers by "Teruo Onishi published in 2007"
TL;DR: In this paper, the authors examined how to study the antenna characteristics using the phantom when extended to a bandwidth including 900 MHz to 3 GHz and 6 to 10 GHz and performed a quantitative study focusing on the electrical constants of the phantom.
Abstract: Previously, the authors studied biological tissue equivalent phantoms able to simulate the electrical constants of the human body in the 3- to 6-GHz band in a single composition ratio. Therefore, in this paper, we examined how to study the antenna characteristics using the phantom when extended to a bandwidth including 900 MHz to 3 GHz and 6 to 10 GHz and performed a quantitative study focusing on the electrical constants of the phantom. The result clearly showed hardly any effect of divergence of the phantom's electrical constants from the target values on the antenna input impedance, radiation efficiency, and radiation directivity. Therefore, in the entire ultra-wideband (UWB), this phantom can be accurately evaluated through antenna characteristic measurements and is clearly effective. Furthermore, differences due to the divergence of the phantom's electrical constants from the target values in the entire UWB bandwidth (3 to 10 GHz) are within ±3% for the average local specific absorption rate (SAR) inside the phantom caused by the electromagnetic wave energy radiated from the antenna. © 2007 Wiley Periodicals, Inc. Electron Comm Jpn Pt 1, 90(5): 48–55, 2007; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/ecja.20300
31 citations
Patent•
17 Oct 2007TL;DR: In this paper, a disclosed specific absorption rate measurement system according to an embodiment of the present invention measures a specific absorption ratio of electromagnetic waves from a radiating source absorbed in a dielectric medium.
Abstract: A disclosed specific absorption rate measurement system according to an embodiment of the present invention measures a specific absorption rate of electromagnetic waves from a radiating source absorbed in a dielectric medium. The system includes a measurement portion that measures a first electric field vector on an observation surface which is a two-dimensional surface in the dielectric medium; an electric field calculation portion that calculates a second electric field vector in a point excluded from the observation surface in accordance with electric field components of the first electric field vector measured on the observation surface, the electric field components being parallel to the observation surface; and a calculation portion that calculates the specific absorption rate from the calculated second electric field vector.
13 citations
Patent•
06 Dec 2007
TL;DR: In this article, an electric field measuring device with a single electro-optical crystal 10 having a refractive index varied according to the intensity of the applied electric field was proposed, and an irradiation device capable of irradiating the crystal with polarized light along three directions orthogonal to each other.
Abstract: PROBLEM TO BE SOLVED: To provide an electric field measuring apparatus capable of easily measuring intensity of an electric field in a plurality of directions at the same position. SOLUTION: The electric field measuring apparatus includes a single electro-optical crystal 10 having a refractive index varied according to intensity of the applied electric field; an irradiation device capable of irradiating the electro-optical crystal 10 with polarized light along three directions orthogonal to each other; and a polarized light measuring device capable of measuring respective states of the polarized light transmitted through the electro-optical crystal 10 in three directions. Preferably, the electro-optical crystal 10 includes a cubic crystal structure, and the irradiation device irradiates the electro-optical crystal 10 with the polarized light along each of three crystal axes of the cubic crystal structure. COPYRIGHT: (C)2008,JPO&INPIT
1 citations
Patent•
15 Nov 2007
TL;DR: In this article, the authors proposed a radio communication terminal for automatically controlling a power state in response to a circumferential state, where an external signal from the external signal generator is transmitted to the control part.
Abstract: PROBLEM TO BE SOLVED: To provide a radio communication terminal for automatically controlling a power state in response to a circumferential state. SOLUTION: The radio communication terminal is used in a radio communication system and receives an external signal from an external signal generator. The radio communication terminal includes: an external signal receiving part for receiving the external signal from the external signal generator; a communication signal transmitting/receiving part for transmitting/receiving a communication signal to/from the radio communication system; and a control part connected to the external signal receiving part and the signal for communication transmitting/receiving part. The external signal receiving part obtains a power state control signal for controlling the power state of the radio communication terminal, based on the external signal from the external signal generator, and transmits the signal to the control part. The control part controls the power state of the radio communication terminal, based on the power state control signal from the external signal receiving part. COPYRIGHT: (C)2009,JPO&INPIT