  We studied magnetic vortex oscillations associated with vortex gyrotropic
motion driven by spin-polarized out-of-plane dc current by analytical and
micromagnetic numerical calculations. Reliable controls of the tunable
eigenfrequency and orbital amplitude of persistent vortex oscillations were
demonstrated. This work provides an advanced step towards the practical
application of vortex oscillations to persistent vortex oscillators in a wide
frequency (f) range of 10 to 2000 MHz and with high values of f/(delta f).
