Hiroyuki Egawa

A small tunable multiband antenna with parasitic elements for mobile applications

We propose a novel tunable multiband antenna with parasitic elements for mobile applications. The proposed antenna covers LTE/WWAN (703-960 MHz, 1447-1510MHz, 1710-2170 MHz, and 2496-2690 MHz) with a small size of 60 mm × 8 mm × 2.3 mm Our proposed antennas configuration consists of two branched 1/4λ monopoles, a parasitic 1/4λ monopole, a parasitic 1/2λ dipole, a dielectric material (ε r = 5.4), and a tunable capacitor. This parasitic 1/2λ dipole technique is a particularly effective method that can increase the bands without reducing the efficiency of the other antenna elements. Also, it does not need a large ground plane compared with the monopole. Because the low band (703-960 MHz) is wideband, the tunable capacitor is used to change the resonance frequency and total efficiency at the low band. The simulated and measured results show a total efficiency more than -3dB in the operation frequencies. The proposed antenna will be a good candidate for mobile applications with the LTE/WWAN operation.

Design of a low SAR multiband antenna for mobile applications

We propose a novel low specific absorption rate (SAR) multiband antenna for mobile applications. Our proposed antennas configuration consists of an antenna ground slit and branched elements to obtain multiband characteristics and low SAR. The proposed antenna covers Long Term Evolution and Wireless Wide Area Networks (703 - 960 MHz, 1447 - 1510 MHz, 1710 - 2170 MHz, and 2496 - 2690 MHz) and can reduce the SAR by at most 45 % compared with a traditional inverted-L antenna. The measured total efficiency of our proposed antenna has been found to vary between -5 dB and -1 dB for target band frequencies. The proposed antenna will be a good candidate for mobile applications with the LTE/WWAN operation.

Low-SAR multiband antenna with ground slit and parasitic elements for tablet computers

We propose a low specific absorption rate (SAR) multiband antenna for tablet computers. The proposed antenna has a ground between it and the body phantom to maintain low SAR. To achieve the multiband characteristics, the antenna has a ground slit and parasitic elements. It covers Long Term Evolution and Wireless Wide Area Networks (703 - 960, 1447 - 1510, 1710 - 2170, and 2496 - 2690 MHz) and is small; 60 × 10 × mm3 and can reduce the SAR by at most 39% (below the limit of 1.6 W/kg) compared with a traditional inverted-L antenna. In this paper, we argue that the proposed antenna is capable of exhibiting multiband and low SAR characteristics.