Fabrication and performance of high T/sub c/ two hole bulk and single hole thick film RF SQUIDs at 77 K

Two-hole YBCO bulk and one-hole YBCO, BSCCO thick-film RF SQUIDs have been fabricated and operated at 77 K. RF SQUID behavior has been studied using commercial RF SQUID electronics with external RF and AF sources. Flux noise density of these SQUIDs depends on the quality of the microbridge. Flux noise present in various reported high-T/sub c/ film RF SQUIDs is compared.