An investigation of dielectric resonator antenna produced from silicon (100) enhanced by strontium doped-barium zirconate films

Dip-coated Ba_1−x Sr _x ZrO₃ thick films with different Ba/Sr ratios (x = 0.0, 0.1, 0.3, 0.5, 0.7 and 0.9) were fabricated on Si (100-orient) substrate at a low temperature of 800 °C via the sol gel method. The experimental results show that dielectric resonator (DR) properties of Ba_1−x Sr _x ZrO₃ films depend on the different Ba/Sr ratios. For structural characterization, the X-ray analysis revealed that phase transformation was affected by the increase in Sr concentrations for heat treatment at 800 °C. The films were crystalline and of single phase. The thickness of one BSZ film is around 1.259 μm when measured using the field emission scanning electron microscope. The BSZ film’s surface morphology as indicated by the atomic force microscopy showed the mean grain size to be in the range of 2.56 to 94.34 μm, and the surface roughness (RMS) was recorded to be between 2.35 to 19.64 nm. The dielectric resonator (DR) properties were measured using a network analyzer. By introducing Ba_1−x Sr _x ZrO₃ (BSZ) films on the high dielectric Si (100-orient) substrate, better frequency stability was achieved i.e. within the range of 8–10 GHz. Measured results show that Si (100-orient) DRA has a 10 dB impedance bandwidth of 4.11% at 9.34 GHz and the BSZ improved this to 11.34% with x = 0.7 at 9.15 GHz. The radiation pattern was observed to be stable throughout the operating frequency and holds good potential for DR applications.