Abstract: A wide-beam microstrip antenna with a metal circular patch as the main radiator is proposed. The antenna operates in the frequency band of 19−21 GHz. Based on this antenna element, a circularly polarized phased array antenna with wide-angle scanning performance is designed. Impedance matching of the microstrip antenna unit is adjusted by loading parasitic periodic circular metal patches. The designed 8×8 array antenna exhibits a gain drop of only 3.5 dBic when scanning within a ±60° beam range, and the gain remains greater than 18 dBic across the entire operating frequency band and at large scanning angles. The antenna unit is easy to process, and the scanning results of the array are as expected, which can be effectively applied to wide-angle scanning phased array antennas.