The BESIII [1] and BaBar collaborations produced data for the $\Lambda$ baryon electric and magnetic form factor's ratio $G_E^\Lambda/G_M^\Lambda$ in the time-like region. By assuming the analyticity of the baryon form factors, a dispersive procedure can be used to analyze the data under a set of theoretical constraints. This prcedure allows to determine the behaviour of the modulus and the phase of the form factor's ratio in the time-like and space-like regions. Different classes of solutions are taken into account, and the results allow to determine crucial properties of the baryon, such as the presence of zeroes of the form factor’s ratio in the space-like region and the baryon's charge radius.