Sk. Khamas et al., INVESTIGATION OF THE ENHANCED EFFICIENCIES OF SMALL SUPERCONDUCTING LOOP ANTENNA ELEMENTS, Journal of applied physics, 74(4), 1993, pp. 2914-2918
The fields backscattered from arrays of electrically small copper and
YBCO superconducting loops are measured and compared with moment metho
d predictions to confirm the gain enhancements and changes in Q factor
s due to increasing the efficiencies of the antenna elements alone, wi
thout the influence of feed and matching networks. Measurements on cop
lanar and parallel loop arrays show only small increases in the backsc
attered fields of the YBCO scatterers, with the largest increase in ef
ficiency being for the single loop. The mutual resistance between elem
ents reduces the benefit of adding more elements to a YBCO loop, to a
greater extent than when copper elements are added to a copper loop.