Integrated Slot Spiral Antenna Etched on Heavily-High Permittivity Piece

Radiation characteristics of printed slot antennas etched on a high permittivity piece 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 material was calculated from the viewpoint of the return loss performance, and it was obvious that the wavelength was reduced by about 37 % using slot antenna etched on a high permittivity piece with a relative dielectric constant of 197. Two types of slot antennas with double and single twin spiral configurations were fabricated by using the high permittivity piece of 10 mm square on a side with a thickness of 2 mm. Each return loss was measured to be larger than 10 dB.