Influence of CuO Addition and Sintering Temperature on Microwave Dielectric Properties of Ca_0.99Zn_0.01La₄Ti₅O₁₇ Ceramics for Application in Stacked Patch Antenna

In this study, the microwave dielectric properties of Ca_0.99Zn_0.01La₄Ti₅O₁₇ (CZLTO) ceramics have been investigated. It is found that the X-ray diffraction pattern exhibited no phase difference with 0.5 wt % CuO additive at different sintering temperatures. The maximum value of the dielectric constant and the quality factor Q×f can be obtained with 0.5 wt % CuO additive and sintered at 1450 °C for 4 h. A τ_f of -8.16 ppm/°C was measured for CZLTO ceramics with 0.5 wt % CuO sintered at 1450 °C for 4 h. The measurement results for a stacked patch antenna at 2.45 GHz are presented. With this technique, a 3.3% bandwidth (return loss < -10 dB) with a center frequency at approximately 2.45 GHz has been successfully achieved. The peak antenna gain is approximately 2.2 dBi, with gain variations of less than 1.0 dBi for frequencies within in the -10 dB S₁₁ bandwidth.