CaxZn(1_x)Al204thin films (x = 0.00; 0 .05 ; 0.10; 0.15 and 0.20) were prepared by sol-gel method with the substitution of Zn2+ by Ca" in the framework of ZnAl204. The effect of Ca addition on the structure and morphology of CaZnAl204thin films was investigated by x-ray diffraction (xRD), field-emission scanning electron microscope (FESEM), energy-dispersive x-ray spectroscopy (EDx), ultra-violet visible (uv-Vis) and atomic force microscope (AFM). The xRD patterns showed the characteristic peaks of face-centred cubic (fcc)ZnAl204and CaZnAl204. The addition of Ca increased the crystallite size from 8.9 to 302 nm. The bandgap of CaxZnuld204 thin film was found in the range of 3.40 to 3.84 eV. sEm micrograph shows the morphology of all thin films is sphere-like, with the grain size increased from 33 to 123 nm. The AFM images show the roughness of surface morphology increased. The substitution of Zn2+ by Ca" increased the crystallite size, grain size and surface roughness which evidently increased the density (4.59 to 4.64 glcm3) and dielectric constant (8.48 to 9.54). The composition of CaxZn(1_x)Al204is considered as suitable material for GPS patch antennas.