Design of 4-8 GHz stochastic cooling equalizers for the Fermilab Accumulator

The 4-8 GHz core stochastic cooling system in the Fermilab Accumulator uses a coaxial cable transmission line to transmit signals from the pickup electrodes to the kicker electrodes. Because of the long length of the cable and the high frequency range of the cooling system, the system suffers a 40 dB gain slope and a 360 degree phase variation across the 4-8 GHz Band. To remedy this situation, a balanced stripline equalizer was designed featuring offset coupled lines and Schiffman phase shifters. The design was optimized by defining an effective bandwidth density and programming the OUTVAR and OUTEQN blocks of the microwave CAD program TOUCHSTONE to maximize bandwidth density