Title :
Analysis of the impedance changes of a HF/VHF monopole antenna in a Brazilian Atlantic rainforest urban site
Author :
Dias, Mauricio H. C. ; Alem, R.A. ; Santos, Jose C. A. ; Nogueira, Evanaska B. ; Vuong, T.P.
Author_Institution :
Secao de Eng. Eletr., Inst. Mil. de Eng., Rio de Janeiro, Brazil
Abstract :
This work analyzes the impact of vegetation coupling on the impedance of a monopole antenna operated in a Brazilian Atlantic rainforest site, in the HF and low VHF bands. A theoretical analysis was performed in order to have a first order estimate of the differences between the impedance responses in a forest spot and in an open area. Next, the impedance of a 3-m monopole was measured in those sites and compared. It was found that the reflection coefficient in forest was slightly shifted in frequency to the left in respect to the open area, as expected from the theoretical estimation.
Keywords :
HF antennas; VHF antennas; monopole antennas; rain; Brazilian Atlantic rainforest urban site; HF-VHF monopole antenna; impedance changes; impedance responses; reflection coefficient; vegetation coupling; Antenna measurements; Couplings; Dipole antennas; Impedance; Vegetation;
Conference_Titel :
Antennas and Propagation in Wireless Communications (APWC), 2013 IEEE-APS Topical Conference on
Conference_Location :
Torino
DOI :
10.1109/APWC.2013.6624931
