“…The main disadvantage of the STO films in comparison with the BSTO films is the necessity of using high control voltages to achieve an acceptable controllability (for STO based capaci tors, it is usually C(0 V)/C(300 V) ≈ 2 [9]). Thus, microwave devices based on the STO films are able to compete with similar BSTO based devices due to the design solutions that can increase the controllability (for example, a decrease in the gap capacitor) with the simultaneous maintaining the dielectric loss at a level not exceeding tanδ = 0.02 at a frequency of 1 GHz and at room temperature [10].…”