  In this paper, a 2-D beam steering mm-wave antenna based on the leaky wave
configuration is presented. Microstrip leaky wave antennas are known to exhibit
beam rotation by changing the frequency. In this work, the microstrip leaky
wave antenna is adopted and co-integrated with electronically tunable board
components that periodically load the antenna. By independent control of
variable capacitors and diodes, single-frequency 2-D beam steering across the
bandwidth is achieved. The proposed antenna is fabricated in Rogers printed
circuit board technologies and the simulation results exhibit a peak realized
gain of 8 dBi, radiation bandwidth of 28-34 GHz, radiation efficiency of more
than 80%, and more than 90$^\circ$ and 70$^\circ$ of beam rotation in the
$\phi$ and $\theta$ directions.
