A New Method of Complex Dielectric Permittivity Determination
The article proposes a new method of complex dielectric permittivity determination based on the use of surface wave resonator. This method is applied to fluorocarbon polymer-4, yttrium stabilized-zirconium and sapphire at frequency band 6-70 GHz.
Irradiation of HTS Josephson junctions with the surface wave resonator
The new type of surface wave resonator (SWR) consists of HTS film on a dielectric substrate is developed. A possibility of optimal coupling between the electromagnetic field of the SWR and the HTS Josephson junction array is shown; The topologies for embedding the bicrystal HTS Josephson junctions in the SWR are developed. These topology ensure the junction synchronization, that can be used for creation voltage standards, microwave detectors and Josephson generators and so on; The microwave properties of the SWR with HTS Josephson junction arrays (up to 450 junctions) and nonlinear elements based on Shottky-barrier diodes have been investigated. For the array with 450 HTS Josephson junctions the voltage sequence with 10 mV step has been obtained, sensitivity of the detector based on this array is 0.1 A/W with dynamic range 10/sup 2/ dB; The Josephson generation with microwave power at several nW for the SWR with bicrystal HTS JJs is detected. There were two groups of junctions. These groups are formed at the time of fabrication due to imperfection of HTS junction fabrication technology.
New microwave circuits for programmable voltage standards using high-temperature Josephson junction arrays
New microwave circuits for voltage standard application containing 256 shunted bicrystal junctions were designed and investigated. The series array follows a meander line, which prevents the uniform distribution of microwave current along the array. To overcome this drawback, we are placing the meander parallel to a coplanar waveguide line. This provides parallel feeding of microwave power to series connected junctions. A circuit divided in 8 sub-arrays represents a seven-bit digital-to-analog converter. At a frequency f=27332 MHz and for a constant power each of the segments of the array demonstrated the first current step at 78 K.