A novel low cost and high performance miniaturized broadband Additive Spiral Antenna (ASA) technology (patent pending) has been developed. Unlike other conventional spiral designs, this new spiral antenna leverages Additive Manufacturing (AM) 3D zig-zag shapes to achieve an efficient slow wave radiation structure for extending spiral's low frequency performance without size increases. Conversely, this 3D additive structure allows a significant antenna miniaturization for the given frequency band, without gain bandwidth performance degradations. As a result, an initial 4″ prototype ASA has been successfully designed and tested with the measured gain bandwidth performance approaching the Chu's fundamental limit for the given antenna size. More importantly, the ASA aperture size is significantly reduced by more than 50% with excellent transmit and receive gain efficiency and power handling capabilities. This paper describes the ASA prototype design and the antenna near field and far field compact range measurement results to demonstrate Additive Manufacturing technology can enhance antenna performance that otherwise not realizable with conventional fabrication techniques.