This paper presents a novel solution to the classical problem of interpolating three-dimensional antenna radiation patterns from two-dimensional, orthogonal pattern slices. We introduce a neural network model that performs this interpolation with high accuracy across a wide range of patterns, including cases where conventional interpolation methods struggle. This model is beneficial for three-dimensional modeling methods, such as ray-tracing, where a full antenna radiation pattern is needed, whereas only principal plane patterns are available from measurements or data sheets. The proposed neural network combines computational efficiency with superior accuracy compared to available alternative methods.