Indium gallium arsenide (InGaAs) is a III–V compound semiconductor with high electron mobility and a narrow bandgap, widely employed in high-speed electronic and optoelectronic devices. However, the intrinsic transport properties of InGaAs, particularly the quantitative understanding of dopant ionization and scattering mechanisms, remain insufficiently explored. In this study, we employed a rotating parallel dipole line (PDL) magnetic system in combination with a Hall bar geometry to investigate the transport properties of Si-doped In0.53Ga0.47As thin films over the temperature range of 170–340 K. The measured mobility exhibited a temperature dependence of µ ∼ T^− 0.94, confirming phonon-dominated scattering, while the carrier concentration increased with temperature due to donor freeze-out behavior. An Arrhenius analysis yielded a donor activation energy of approximately 6.8 meV, corresponding to a shallow Si donor level and showing good agreement with theoretical predictions. These findings provide direct insight into the intrinsic transport characteristics of In0.53Ga0.47As and offer valuable reference data for the future design of high-speed electronic and optoelectronic devices.