High Tc superconducting CPW bandstop filters

Quantum wave bandstop filters

We propose and demonstrate, based on the concept of a microwave bandstop filter, two quantum wave bandstop filter structures. Both structures employ nanoscale gates in a heterojunction transistor to induce a quantum cavity connected by two one-dimensional wires. As the electron wavelength is changed by the gate voltage, we observed that, at certain gate voltages, the transmission of electron wa...

Applications using high-Tc superconducting terahertz emitters

Using recently-developed THz emitters constructed from single crystals of the high-Tc superconductor Bi2Sr2CaCu2O8+δ, we performed three prototype tests of the devices to demonstrate their unique characteristic properties for various practical applications. The first is a compact and simple transmission type of THz imaging system using a Stirling cryocooler. The second is a high-resolution Mich...

Design of sharp FIR bandstop filters using quadrature masking filters

A novel computationally highly e cient realization of sharp symmetrical bandstop FIR lter is proposed. The new structure is derived using the frequency-response-masking technique, where the bandedge-shaping lter is derived from half-band lter by substituting each delay of the half-band lter by M delays. The masking lters are unconventional. They are quadrature lters derived from linear combinat...

Miniaturized Bandstop Filters Using Slotted-Complementary Resonators

This paper presents a technique to miniaturize bandstop filters applicable for radiofrequency/microwave applications. The technique comprises the use of small resonant inclusions bridged with a slot, etched from the metallic ground plane underneath the filter’s microstrip line segment. Unlike artificial magnetic materials, for instance split-ring resonators (SRRs) that respond to vertical magne...

High Tc Superconducting Flux Flow Transistors : Potential Performances and Problems