  We report an efficient technique to induce gate-tunable two-dimensional
superlattices in graphene by the combined action of a back gate and a few-layer
graphene patterned bottom gate complementary to existing methods. The patterned
gates in our approach can be easily fabricated and implemented in van der Waals
stacking procedures allowing flexible use of superlattices with arbitrary
geometry. In transport measurements on a superlattice with lattice constant
$a=40$ nm well pronounced satellite Dirac points and signatures of the
Hofstadter butterfly including a non-monotonic quantum Hall response are
observed. Furthermore, the experimental results are accurately reproduced in
transport simulations and show good agreement with features in the calculated
band structure. Overall, we present a comprehensive picture of graphene-based
superlattices, featuring a broad range of miniband effects, both in experiment
and in theoretical modeling. The presented technique is suitable for studying
more advanced geometries which are not accessible by other methods.
