A circularly polarized stub-matched inverted L-shaped antenna for C-band applications is presented in this communication. Antenna parameters of inverted L-shape on the radiating patch and slits, notch, square strips and stub on the ground plane and the effect of these are analyzed. The proposed optimized antenna (A5: 0.54λ0 × 0.54λ0 × 0.02λ0 mm3) is selected among antennas (A1 – A5) with 5.1 GHz design frequency after simulation through high-frequency structure simulator (HFSS). Circular polarization is obtained by introducing stub/perturbation on the ground plane. By introducing stub, the highest measured (S11 < − 10 dB) impedance bandwidth of 50.9% (3.48 – 5.86 GHz) is observed amongst the reported and compared bandwidths. Peak gain of 5.32 dBi and 3 dB axial ratio bandwidth of 16.2% (4.71 – 5.54 GHz) is reported in the present work. An antenna is useful in the entire downlink frequency (3.7 – 4.2 GHz) of the C band.