Reliability and Stability of Novel Tunable Thin Film

Abstract

AbstractA new process has been developed in Paratek Microwave Inc. to formulate stable tunable (Ba, Sr)TiO3 (BST) based thin film material. Varactors, with a co-planar structure, were fabricated by using the new material. The varactor Q of 105 tested at 2 GHz was observed with average tunability of 58 % at 150V (37.5 V/μm). The lifetime tests indicated that this material is very stable under continuous 100 to 150 V dc bias both at the room temperature and in 70 °C environment. Thus, this novel tunable thin film material opens a new avenue to develop high quality tunable microwave devices. Tunable IF filters have been built by using this novel material for microwave backhaul radios and handset applications. Initial results of a RF phase shifter are also included and demonstrate another application of these films.