M10.6.7: Design and manufacturing of high linearity multichannel downconverter

To achieve the required beam stability for the FLASH a cavity field stability for the accelerating sections in amplitude of 0.01% and in phase of 0.01 degree the design of a high performance multichannel downconverter was necessary. The designed module can operate with both 1.3 GHz and 3.9 GHz input frequencies used at FLASH. This milestone concerns designing of an eight-channel prototype downconverter and its performance evaluation. Specification for the designed module is given and the design issues are described in the following sections of this report. The last section of this document contain measurement results, conclusions and future plans for the developed device.