  We report radio frequency (rf) electrical readout of graphene mechanical
resonators. The mechanical motion is actuated and detected directly by using a
vector network analyzer, employing a local gate to minimize parasitic
capacitance. A resist-free doubly clamped sample with resonant frequency ~ 34
MHz, quality factor ~ 10000 at 77 K, and signal-to-background ratio of over 20
dB is demonstrated. In addition to being over two orders of magnitude faster
than the electrical rf mixing method, this technique paves the way for use of
graphene in rf devices such as filters and oscillators.
