| 摘要 |
PROBLEM TO BE SOLVED: To keep dielectric characteristics and to improve deflective strength by allowing the subject composition to consist essentially of a multiple oxide composed of a specific composition of MgO, Al2O3 and SiO2 and contain >=1 kinds among Sr, In, Ni, Co, Ga, Zr and Ti and Si3N4 in a specific ratio. SOLUTION: The molar ratio composition formula of reach component of MgO, Al2O3 and SiO2 is expressed by xMgO-yAl2O3-zSiO2. Where x=10-40, y=10-40, z=20-80 and (x+y+z)=100 by mol%. Sr, In, Ni, Co, Ga, Zr and Ti are contained by 0.1-15.0 wt.% expressed in terms of oxide and Si3N4 is contained by 0.1-60.0 wt.%. As the dielectric characteristics, specific dielectric constant of 4.5-6.0 and Q value of >=1,000 in 60 GHz measuring frequency are attained. An NRD guide is preferably formed by providing a dielectric plate 2 having the above composition between parallel flat plate conductive bodies 1, 3 arranged at an interval of <=λ/2 to the wavelength λ of high frequency signal and a millimeter wave integrated circuit or the like is miniaturized. |
