A novel small microstrip patch antenna with a C-shaped slot is presented in the paper. The size of the antenna is only 33% of a conventional microstrip patch antenna and is much easier for fabrication than shorted patch antennas. The antenna is theoretically investigated using finite-difference time-domain (FDTD) method and its return loss and radiation properties are presented. For purpose of comparing

method of moment (MoM) results and measured results are also presented and good agreement is achieved. Such an antenna may be useful for applications where reduced antenna size and simplicity are major concerns.