Design for multiband relay antenna with parasitic monopoles

This paper presents a multiband antenna composed of one main monopole and four parasitic poles for the in-building mobile relay system including a firefighting radio band. A main center pole is resonated at 450 MHz of the firefighting band, parasitic poles are considered for the multi-resonance and the beam direction control. The measured results such as the reflection coefficients and the radiation patterns of a fabricated antenna are shown reasonable agreement with the prediction.