List of Low‐Loss Ceramic Dielectric Materials and Their Properties

Abstract

AbbreviationsST = sintering temperature ( • C) r = relative permittivity , f = measurement frequency (GHz) f = coefficient of temperature variation of resonant frequency (ppm/ • C) No. = serial number Qf = quality factor frequency product (GHz)The table lists the key property data of microwave dielectric materials available from published materials. These data are the relative permittivity ( r ), the product of the Q-factor and the frequency (Qf ), the frequency of measurement (f), and the temperature coefficient of the resonant frequency ( f ). In tabulating these data, we make no judgment on the measurement method and the reliability of the result. It is known that the ceramic properties such as porosity, grain size, raw materials used, impurities, measurement methods, and equipment used for measurements affect the dielectric properties and readers should be aware that exact comparison of data on materials of identical composition and manufactured in different laboratories using different processing conditions and measured by different methods would be expected to lead to small variations in properties. The data of dielectric measurements carried out using impedance methods at low (MHz) frequency is excluded as the errors in these methods mean that a loss tangent less than 10 −3 is unreliable. The data are arranged in the order of increasing relative permittivity. The quality factor of the microwave dielectric ceramics decrease significantly with increasing relative permittivity, as shown in Figure A.1. The inset in the figure shows the variation of quality factor frequency product with Microwave Materials and Applications, First Edition. Edited by Mailadil T. Sebastian, Rick Ubic and Heli Jantunen.