Novel printed slot antennas are demonstrated in this thesis. For the linear polarization design, CPW-fed strip-loaded square slot antenna is presented for achieving broadband operations. For the circular polarization, two novel antenna designs are also presented¡Fone is a CPW-fed square slot antenna with an inverted L tunning stub, and the other is a microstrip line-fed square slot antenna with a conducting strip from ground plane for broadband circularly polarized radiation. Finally, an antenna design having compact size and broadband characteristic is shown.

Novel designs of printed slot antennas have been investigated in this dissertation. For the linearly polarized designs, the study of single-feed dual-frequency printed slot antennas with an open-ring conducting strip is first presented. In addition, a novel design of dual-frequency dual-loop printed slot antenna is described. As for the broadband printed slot antenna designs, a printed semicircular slot antenna with a microstripline feed is shown. The impedance bandwidth obtained reaches about 46%. For the circularly polarized designs, we propose a circularly polarized microstrip antenna with an asymmetry of the antenna structure. By choosing a suitable meandered slot, CP operation can be obtained. Finally, we apply the design concept of CP operation using a shorted section to achieve a circularly polarized printed slot antenna design. The obtained CP bandwidth of this design is greater than 8%.