shape thus the antenna has the semicircular antenna component 100 preferably shaped into a sideward u201c u u201d shape i e u201c u201d formed on the dielectric plate 10 curve u201c c u201d indicates an anti resonant point generated in the vicinity of 5 1 ghz therefore good vswr characteristics cannot be expected from the bent semicircular monopole antenna also the antenna component 100 is bent so as to be of the same shape on its front and rear surfaces such as illustrated in fig6 a hence current flows with opposite phases through the front and rear surfaces of the antenna component 100 as a result a frequency band is created whose loss increases due to factors including the material of the dielectric plate 10 thereby reducing radiation efficiency meanwhile the inventive antenna denoted by curve u201c a u201d does not have on the average as good vswr characteristics as the conventional circular disc monopole antenna denoted by curve u201c b u201d however the inventive antenna does not create an anti resonant point considering the tradeoff relation between the area of the antenna and its performance the inventive antenna can be said to have satisfactory vswr characteristics while the invention has been shown and described with reference to certain preferred embodiments thereof they are merely exemplary applications for example the present invention is also applicable to a dipole antenna the term u201c dipole u201d will also be recognized to cover u201c cross dipole u201d antennas fig7 a and 7b are side views of a dipole antenna according to the present invention referring to fig7 a and 7b.