High-Tc Superconducting Filters for Wireless Communication

Superconducting microwave devices can realize future wireless communication systems with higher selectivity, higher sensitivity and smaller power consumption. We firstly fabricated microwave bandpass filters of a high-temperature superconducting oxide NdBa2Cu3O7, which is superior to the widely-used superconductor YBa2Cu3O7 in various properties including the superconducting transition temperature Tc and the surface resistance Rs. The filters were fabricated using high-quality films obtained by NTT-original thin film-growth technique for molecular-beam epitaxy (MBE) of high-Tc superconducting oxides. Improving the performance of the new filters, we may realize application of superconducting filters for transmitting parts in wireless systems, which is supposed to give remarkable reduction in size and power consumption of the systems.