  We propose a pulsed dynamical decoupling protocol as the generator of
tunable, fast, and robust quantum phase gates between two microwave-driven
trapped ion hyperfine qubits. The protocol consists of sequences of
$\pi$-pulses acting on ions that are oriented along an externally applied
magnetic field gradient. In contrast to existing approaches, in our design the
two vibrational modes of the ion chain cooperate under the influence of the
external microwave driving to achieve significantly increased gate speeds. Our
scheme is robust against the dominant noise sources, which are errors on the
magnetic field and microwave pulse intensities, as well as motional heating,
predicting two-qubit gates with fidelities above $99.9\%$ in tens of
microseconds.
