95results about How to "Reduce SAR" patented technology

A mobile radio apparatus antenna for improving the gain and widening the band is provided. A inverted-L antenna (10) is a feed element with one end thereof electrically connected to one plate surface of a circuit board (12) through a feed point. The circuit board (12) is a circuit board of a mobile radio apparatus, to which the circuit parts including the inverted-L antenna (10) are connected. A planar antenna (14) is provided facing the backside plate surface of the plate surface of the circuit board (12), to which the inverted-L antenna (10) is connected, and is a parasitic element with an electrical length in the length direction set to approximately ½ of the wavelength of radio waves communicated by the mobile radio apparatus. Here, the dimension of the inverted-L antenna (10), the circuit board (12), and the planar antenna (14), and the distance therebetween are adjusted to predetermined values, so as to change the self-impedance of the inverted-L antenna (10), the self-impedance of the planar antenna (14), and the mutual impedance between the inverted-L antenna (10) and the planar antenna (14).

An MRI apparatus comprises a waveform controlling means for calculating a radio frequency pulse and applying the pulse to an irradiating means, and the waveform controlling means reads out a radio frequency pulse waveform vector from a first memory means which memorizes multiple radio frequency pulse waveform vectors, calculates a simulated irradiation pattern, and calculates a radio frequency pulse waveform which gives the minimum value of weighted sum of squares of differences of absolute values and squares of differences of phases for an ideal irradiation pattern and the simulated irradiation pattern. An RF pulse waveform showing superior ideal irradiation pattern reproducibility and providing reduced power of the RF waveform is formed, and safety of MRI subject is improved by performing imaging using such an RF pulse.

The invention discloses a wideband low-specific absorption rate (SAR) wireless terminal antenna system. The wideband low-SAR wireless terminal antenna system comprises a printed circuit board (PCB), an antenna bracket, an antenna and a metal piece, wherein the antenna bracket is arranged on the PCB; the antenna covers the outer surface of the antenna bracket; the metal piece covers the inner surface of the antenna bracket; the antenna comprises a main body and two ends; at least one end of the antenna has a bending structure, and a certain gap is formed between the bending structure and the main body; a projection of the metal piece on the inner surface of the antenna bracket at least covers part of the gap; and the metal piece is used for improving capacitance between the bending structure and the main body, so an electric field of the gap between the bending structure and the main body is reduced, and an SAR value is decreased. Compared with the prior art, the wideband low-SAR wireless terminal antenna system is wide in resonant frequency, low in SAR, simple in structure and easy to implement.