9632811 Anlarge Our objective is to develop new methods of imaging microwave frequency magnetic fields and currents on micron length scales and sub-rf-period time scales in microwave devices. These imaging techniques will open up a new microscopic understanding of microwave device properties. Special attention will be given to superconducting microwave devices as they are now poised to make significant inroads into the cellular telephone and PCS markets. The key limitations to this new technology, beside reliable cryogenic cooling, is the problem of power dependence and nonlinearity of the devices. Our imaging techniques will be specifically focused on the understanding and compensating for the microscopic origins of power dependence and nonlinearity in these devices. The imaging techniques to be employed include scanning microwave microscopy, bolometric and non-bolometric scanning local energy deposition, and scanning SQUID microwave microscopy. ***