Dual frequency coplanar triangular monopole antenna

This paper presents a new microstrip-fed dual frequency printed triangular monopole antenna, which can be used in one radiating element and in tunable frequency ratio. Furthermore, due to the increased effective current patch in the triangular monopole, as compared with a simple strip monopole of the same length, the required monopole length at a fixed operating frequency can be reduced. That is, the electrical length of the proposed antenna is less than one quarter of a wavelength.