AbstractThe aim of this study is to present guidelines to design a helicone antenna (helix with conical ground conductor) with an optimum gain while keeping the physical size of the antenna as small as possible. To this end, variations of the antenna gain with the dimensions of the conical ground, including its inner diameter, height, and angle, are numerically computed, and guidelines for accelerating the design and optimization of the antenna are extracted. Note that, in most of applications, a trade‐off between physical compactness and performance of an antenna has to be made. Thus, in this investigation, the guidelines are developed with the aim of achieving a compromise between the maximum radiation gain and minimum physical dimensions. It is shown that following the proposed design guidelines the gain of a helical antenna can be increased up to 5 dB, while the antenna has an acceptable physical size.