Benabdallah, A.2; Caputo, J. G.2; Scott, Alwyn C.1
1 Department of Informatics and Mathematical Modeling, Technical University of Denmark2 Institut National des Sciences Appliquées de Rennes
We introduce an exponentially tapered Josephson flux-flow oscillator that is tuned by applying a bias current to the larger end of the junction. Numerical and analytical studies show that above a threshold level of bias current the static solution becomes unstable and gives rise to a train of fluxons moving toward the unbiased smaller end, as in the standard flux-flow oscillator. An exponentially shaped junction provides several advantages over a rectangular junction including: (i) smaller linewidth, (ii) increased output power, (iii) no trapped flux because of the type of current injection, and (iv) better impedance matching to a load.
Physical Review B Condensed Matter, 1996, Vol 54, Issue 22, p. 16139-16146