Title :
The pentagonal planar monopole for digital mobile terminals; bandwidth considerations and modelling
Author_Institution :
Sch. of Electron. & Commun. Eng., Dublin Inst. of Technol., Ireland
Abstract :
A planar monopole antenna employing a square geometry has been analysed and proposed as a wideband antenna for digital mobile terminals. This antenna suffers little degradation of the radiation pattern within the impedance bandwidth. Previous attempts have been made, both to enhance and control the impedance bandwidth of the antenna. These include the addition of a shorting post which reduced the lower edge frequency by introducing an extra mode (yielding the shorted planar monopole), tilting the planar element with respect to the groundplane and employing and a trapezoidal geometry. The impedance bandwidth of the square element is dependent on the feedgap and the optimised value of the impedance bandwidth ratio (IBR) is 2.4:1 for the simple square planar element and 4:1 for the shorted planar element. A significant bandwidth enhancement can be achieved by trimming the square edge near the groundplane yielding a pentagonal monopole
Keywords :
antenna radiation patterns; digital radio; electric impedance; land mobile radio; mobile antennas; planar antenna arrays; bandwidth enhancement; digital mobile terminals; feedgap; groundplane; impedance bandwidth control; impedance bandwidth ratio; lower edge frequency reduction; pentagonal planar monopole; radiation pattern; shorted planar element; shorted planar monopole; shorting post; square geometry; square planar element; trapezoidal geometry; wideband antenna;
Conference_Titel :
Antennas and Propagation, 2001. Eleventh International Conference on (IEE Conf. Publ. No. 480)
Conference_Location :
Manchester
Print_ISBN :
0-85296-733-0
DOI :
10.1049/cp:20010243
