Internet of things (IoT) devices require antennas with quasi-isotropic radiation patterns to maintain orientation-insensitive communication. In this work, various combinations of azimuthal electric current rings on a sphere for quasi-isotropic radiation are investigated. A novel theoretical model is proposed to synthesize an antenna with a quasi-isotropic radiation pattern. The synthesis approach demonstrates a gain variation of 2.43 dB on a sphere with a radius of 0.08 λ (ka = 0.5). Inspired by the proposed synthesis model, a practical antenna is designed accordingly with a gain variation of 4.6 dB at 915 MHz, which is suitable for IoT applications.