Radiation Characteristics of Integrated Traveling-Wave Antenna Etched on Heavily-High Permittivity Substrate for Size Reduction

Radiation characteristics of printed antennas etched on a high permittivity dielectric substrate with a relative dielectric constant of 197 were investigated for the purpose of miniaturization of antennas. At first, the effect of shortening of the wavelength caused by use of the high permittivity dielectric substrate was calculated from the viewpoint of the directive gain performance, and it was obvious that the wavelength was reduced by 20 % for the permittivity of the substrate. Two types of antennas with spiral and meander configurations were fabricated by using the high permittivity dielectric substrate of 10 mm square on a side, having a thickness of 2 mm. Each return loss was measured to be larger than 20 dB and its radiation pattern was similar to that of an omni-directional antenna with an absolute gain of 0 dBi