A linear-to-circular polarization conversion transmitter is proposed using 3 × 3 periodic metallic strips, which are twisted 900 in the upper and bottom layers. The metallic strips are printed on both sides of the dielectric substrate that are subjected to enhance the axial ratio bandwidth at resonance frequencies. The proposed structure is excited by a normal incident of x-linearly polarized wave, after transmission, it decomposed into two orthogonal linear components through structure have equal magnitudes and 900 phase difference between them. Numerical simulation results indicate that the incident x-polarized wave converts into a right handed circularly polarized (RHCP) wave at 12.0 GHz - 14.59 GHz and left handed circularly polarized waves (LHCP) are achieved at 14.83 GHz - 15.63 GHz, 15.80 GHz -16.51 GHz and 17.13 GHz - 18 GHz, respectively. The accumulative axial ratio of Txx, Txy 33.06% is obtained at four frequency wide bands. The measured results are in very good agreements to numerical simulation results.