A miniaturized microstrip-fed, wideband and circularly polarized L-shaped slot antenna is designed for ultra-wideband applications. To realize L-shaped slot antenna with wide impedance bandwidth, a stub of size 10.7 mm2 is added to a rectangular shaped slot of the ground plane. The position of the feedline is optimized to attain wide circular polarization bandwidth. The proposed antenna size is very small ie, 25× 25 mm2. A prototype of the design is fabricated and measured. The axial ratio bandwidth (ARBW< 3 dB) of 2.2 GHz (from 6.2 GHz to 8.4 GHz) and the impedance bandwidth (S11<-10 dB) of 7.4 GHz (from 2.5 GHz to 9.9 GHz) is achieved by the proposed design. Moreover, the antenna achieves a stable radiation pattern and a gain of more than 2.8 dBi over the complete ARBW. The advantages of the structure are miniaturized design, having wide impedance bandwidth, and broad ARBW.