A highly efficient prototype inexpensive dielectric antenna in the millimeter wavelength region has been designed. Plastic single paraboloid reflector quasi-optical lens dramatically increase the signal strength between 30 GHz to 300 GHz. A number of different designs were tested but the present design provides a better collimation and focusing of the millimeter wavelength beam. The aperture-limited horn was used due to relative compactness. The different dependence of the radius of curvature of the wave-fronts on distance from the beam waist, the familiar formulas are somewhat modified. This antenna is small, low weight and robust against high winds.