  Large field inflation models are favored by the recent BICEP2 that has
detected gravitational wave modes generated during inflation. We study general
large field inflation models for which the potential contains (constant)
quadratic and quartic terms of inflaton field. We show, in this framework,
those inflation models can generate the fluctuation with the tensor-to-scalar
ratio of $0.2$ as well as the scalar spectral index of $0.96$: those are very
close to the center value of the tensor-to-scalar ratio reported by BICEP2 as
well as Planck. Finally, we briefly discuss the particle physics model building
of inflation.
