TUNABLE FILTERS USING CHARGE TRANSFER DEVICES

摘要

The report summarizes progress in the development of a tunable CCD bandpass filter. Several design approaches are discussed, and experimental data are presented for three filter designs: (1) a 101-stage filter designed for 29 dB sidelobes and a 4% bandwidth at 3 dB, (2) a 500-stage filter designed for 42 dB sidelobes and 1% bandwidth at 3 dB, and (3) a buried channel 403-stage filter having 35 dB sidelobes and a 1.2% bandwidth at 3 dB. Computer simulations of the filters were made, including effects of charge transfer loss and tap weight error, to determine filter limitations and design criteria. An integrated differential current integrator is described. An integrated input amplifier for better noise performance is discussed. (Modified author abstract)