Very Low-Noise Figure HTSC RF Front-End

Abstract

A very low noise figure radio frequency (RF) front-end for the cellular realm is presented. The front-end is composed of two planar YBCO high critical temperature superconductor (HTSC) bandpass filters (BPFs) and a low temperature, low noise amplifier. Using advanced HTSC growth techniques, 8-pole hairpin BPFs are implemented in a YBCO thin film grown on both sides of a sapphire substrate. The front-end is designed and implemented based on the optimal configuration of the filters derived from advanced electromagnetic simulations. Measured performance at 77 K shows a high-frequency response and very low losses, with an insertion loss of 0.15 dB and a rejection ratio of −93 dBc. The integration of HTSC filters with the low noise amplifier results in a system with superior performance, with a low noise figure of around 0.5 dB. Low insertion loss and the compact dimensions of the filter, along with low total system noise, make the designed superconducting RF front-end highly attractive for radio receivers.

Efficiency Improvement of an Electric-Grid Transformer Using the Diamagnetism Characteristics of a Bulk Superconductor

“…Figure 5 shows the transformer model with the cladding of a bulk superconductor material over the air gaps between the two core parts and on the sides between the core and the secondary copper winding. In order to simulate the superconducting effects of the YBCO bulk material used for the magnetic shielding, we used a perfect electric conductor (PEC) material [24][25][26][27][28][29][30].…”