Magnetically modulated microwave absorption in ceramic high-T c superconducting samples

Previously we have proposed a model of magnetically modulated microwave absorption (MMMA) which assumes formation of superconducting current loops closed by Josephson junctions and well explains the origin and properties of the periodic signal in HTS monocrystals. Now we try to explain the origin of a broad low field MMMA line in ceramic samples by treating this signal as a sum of many periodic signals arising from individual grains.