Crystal structure, microwave dielectric properties, and dielectric resonant antenna studies of novel low-permittivity CoAl2O4 spinel ceramics

CoAl2O4 spinel ceramics were prepared via a standard solid-state reaction method, and their crystal structure, microwave dielectric properties, resonant antenna applications systematically investigated in this study. X-Ray diffraction patterns Raman spectra confirmed that belongs to the Fd-3 m space group with cubic symmetry. εr Qf values increased increasing sintering temperature, where an ever-improving microstructure was also observed from scanning electron micrographs. The optimal properties achieved as follows: = 9.34, 30,500 GHz, τf −54 ppm/°C. Moreover, designed simulated demonstrate application prospects of towards antennas. CoAl2O4-based resonating at 14.33 GHz exhibited high return loss −40.9 dB, wide impedance bandwidth 940 MHz, exceptionally total efficiency 96.6%. remarkable performances suggested promising candidates for wireless communication devices operating Ku-band, provided can be further tuned toward zero.