The Gate Undercarriage is a great way to install a gate - fully functioning without cement or driving posts in the ground.  The steel undercarriage is buried 18 to 24 inches under the ground and makes the gate a single structure. 

The gate and undercarriage can be configured with the automatic gate controller so all you have to do is place the gate in the trench, bury it and plug it in to power.

click here to see a 3-D version of this gate.