Designing Multiband, Reconfigurable Printed Antenna for Modern Communication Systems

kground and Objectives: Printed monopole antenna has an omnidirectional radiation pattern but a narrow impedance bandwidth. To achieve multiband behavior, modification of the antenna shape is necessary. There is no systematic approach for the shape modification and commonly it is done by parametric studies, adjusting, tuning or optimization of an initial shape.Methods: The method for designing a multiband antenna is based on transmission line theory and lumped element model. It applies to all desired multiband operations without needing tuning or optimizing a complex configuration. Every length and dimension are computed from the mathematical formula or Smith chart as a graphical tool. The proposed matching method in the design of a multiband and reconfigurable CPW-fed monopole antenna employed. Both series and parallel impedance matching stubs are investigated and compared with each other.Results: To explain the challenges, the proposed method was applied to a desired antenna. It showed that using matching stubs in the CPW line can design a multiband and reconfigurable antenna. Also, the measurements have been done and compared with the simulations and show a good agreement.Conclusion: Compared to the microstrip line, the CPW feeding of the monopole antenna has the advantage that both parallel and series stubs can be implemented for the matching of the antenna. In this case, the required space for these stubs placed inside the antenna and no extra space needed. So, the printed size of the proposed antenna does not change. The impedance matching method for the integrated stubs with the antenna has been proposed. The high-pass and low-pass properties of each matching network were considered. The authors showed that this method can successfully design multiband, reconfigurable CPW-fed monopole antennas.

کلیدواژه ها:

CPW-fed Monopole Antenna ، Impedance Matching Stubs ، Multiband ، Reconfigurable