Study on Ultra-Small Sized Antennas Using High Permittivity Ceramics at V/UHF Bands

尽管移动通信的设备和电路有小型化的趋势，但由于其波长依赖性，相关的天线在结构小型化方面存在困难。实际上，微带天线、f形天线等天线的小型化研究和开发已经被许多研究所、公司和实验室所推动。本研究的目的是基于高介电常数材料的波长衰减效应，开发一种新型的小尺寸天线。利用介电常数为90的材料，在300MHz频段成功研制了面积为2cm × 1cm的平面天线。该天线具有圆极化、高效率、体积小等特点。此外，在超高频波段设计并开发了一种基于自互补结构和行波辐射特性的新型天线。由此可见，该天线具有从甚高频到深超高频的超宽带运行优势，且结构体积小。应用该技术已成功开发出无线局域网、3G PDC、蓝牙等移动通信系统的新型小尺寸天线。

Although there is a tendency to miniaturize the devices and circuits for mobile communications, the related an tennas have a difficulty in miniaturizing their structures due to their wavelength dependence. Actually, research and development for size reduction of the antennas such as microstrip antennas and F-shaped antennas have been promoted by many institutes, companies and laboratories.The purpose of this research is placed on the development of a new type of small sized antennas based on the wavelength reduction effect of the high permittivity materials. By using the materials with the permittivity of 90, the planar antenna having the dimensions of 2cm X 1cm in area has been developed successfully at 300MHz band. This antenna has some interesting properties such as circular polarization, high efficiency, and size reduction.Moreover, novel antenna, which is based on the self-complimentary structure and the traveling wave radiation nature, has been devised and developed at UHF band. It is obvious that this antenna has great advantages of ul tra-wide band operation from VHF to deep UHF as well as small sized structure.The new types of small sized antennas for mobile communication systems such as wireless LAN, 3G PDC, blue-tooth, and so forth, have been developed successfully by using them.