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We have observed intrinsic Josephson effects for current flow perpendicular to the CuO2 planes in HTSC thin films. Tl-Ba-Ca-Cu-O thin films were deposited on step edges in LaAlO3 substrates. Due to the special preparation process, microbridges across such steps act as stacks of intrinsic Josephson junctions with current flow perpendicular to the CuO2 planes (STEP STACK junctions). Up to 130 individual junctions could be observed exhibiting high IcRN products up to 26 mV per junction. We observed ac-Josephson effects as Shapiro steps and in microwave emission experiments. At low temperatures sharp emission peaks were detected at frequencies of 11.3 and 24.2 GHz. Broad emission peaks from the whole stack were observed at temperatures close to Tc.

High performance narrowband bandpass filters are required in satellite communication systems. Especially HTS filter banks are particularly attractive because of their low insertion loss and sharp filter skirts needed in input multiplexers. T1,Ba,CaCuZO, thin f i l m s on 2"-LaAlO,-substrates and 10xlOmmz-sapphire substrateswere prepared using a two s t e p technology. A TI-free precursor film is prepared by sputtering. The TI-incorporation is performed by annealing in a T1,O loaded atmosphere. The best films show surface resistances below 1OOp C2 at 77K and 4GHz. Two-pole bandpass-filters with a center frequency of 4GHz and a bandwidth o f 17.5MHz using dual-mode ring resonators have been fabricated from the films on LaA10,. The measured passband shape achieved with tuning elements is in good agreement with t h e specifications of the design.

Abstruct-Step edge Josephson junctions and dc SQUIDs made of laser ablated and sputtered YBCO films and grain boundary junctions in polycristalline TBCCO films have been investigated. Bridges in the micrometer scale have been structured by laser or ion beam etching as well as by the inhibit-layer technique. The Josephson junctions are characterized comparing I-V measurements under microwave irradiation to calculations within RSJ model with finite capacitance and white noise. The dependence of the IcR, product on temperature can be fitted to microscopic theory of SNINS or SNS junctions with additional temperatureindependent pair breaking. Flux modulation and noise properties of the dc SQUIDs at 77 K are shown.

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