Advances on Microwave Ceramic Filters for Wireless Communications (Review Paper)

<p>A review of the technological developments on ceramic monoblock filters and duplexers over the years is presented in this work. Early designs based on simulated and measured data are presented along with later designs based on accurate equivalent circuits as well as the use of evolution algorithms for optimal design. </p>

Dielectric Characteristics of (Ca0.2Sr0.8)3(ZrxTi1-x)2O7 Ceramics at Microwave Frequencies

(Ca0.2Sr0.8)3(ZrxTi1-x)2O7 (x = 0.02-0.1) ceramic prepared by the solid state method was investigated for its microstructure and microwave dielectric properties. The correlation between the microstructure and microwave dielectric properties was also investigated. By increasing x from 0.01 to 0.06, the dielectric constant and Q×f value of the specimen could be increased from 72 to a maximum of 74, and from 11000 GHz to a maximum of 18000 GHz, respectively. The εr value of 74, the Q×f value of 18,000 GHz, and the τf value of 418 ppm/oC were obtained for (Ca0.2Sr0.8)3(Zr0.06Ti0.94)2O7 ceramics sintering at 1520oC for 4h, and (Ca0.2Sr0.8)3(ZrxTi1-x)2O7 (x = 0.02-0.1) is proposed as a suitable material candidate for application in microwave ceramic temperature sensing antenna.

The Application of Microwave Ceramic in Filter-Antenna Module for WLAN System

In this paper, the simulation and measurement results of a filter-antenna module for application in WLAN band are presented. The filter-antenna module is fabricated on microwave ceramic substrate. The filter-antenna module is consisted of a monopole antenna, two U-shaped microstrip half wavelength resonators, and a tapped open stub. The proposed filter-antenna module has good agreement between the measurement and the simulation results. At center frequency, electromagnetic coupling between two half-wavelength resonators and inverted-L shaped microstrip feed line occurs and contributes the radiation. At the harmonic frequency, the currents are mainly distributed around the tapped open stub. The proposed filter-antenna module has a 10 dB return loss with bandwidth 290 MHz (2,337 - 2,627 MHz), covering the WLAN band.

Hafnium silicate: a new microwave dielectric ceramic with low thermal expansivity

Hafnium silicate: a low thermal expansion microwave ceramic.