A coplanar type lumped-element 6-pole microwave Chebyshev bandpass filter (BPF) of center frequency (f0) 2.0 GHz and fractional bandwidth (FBW) 1.0 % was designed. For the design method, theory of direct coupled resonator filters using K-inverters was employed. Coplanar type lumped-element BPFs are composed of a meander-line L and interdigital C elements. The frequency response was simulated and analyzed using an electromagnetic field simulator (Sonnet-EM). Further, the changes in f0 and FBW of the BPF were also realized by the mechanical tuning method.

Ferroelectric / superconducting heterostructures of Pb(Zr0.52Ti0.48)O3 [PZT] / (Y0.6Pr0.4)Ba2Cu3Oy [YPBCO] have been formed on SrTiO3(100) substrate using an ArF pulsed laser deposition. The crystallinity and surface morphology of heterostructures were investigated by X-ray diffraction measurements and atomic force microscopy. We also measured dielectric and ferroelectric properties of PZT film in the Au/PZT/YPBCO structure. Furthermore, we fabricated a three-terminal devices having the structure described above using an in-situ metal mask exchange system, and investigated the ferroelectric field effect. As a result, we observed a modulation of channel resistance approximately equal to that estimated from the induced carrier and memory effect due to remanent polarization of PZT.