I opened two different GSM antenna housings as shown on the images.
The first image shows the RF SOLUTIONS ANT-GHEL2R-SMA antenna, which is an helical 1/4 wave monopole antenna.
The second image is the SIRETTA DELTA2C/X/SMAM/S/RA/25, which is, according to its datasheet, a dipole antenna.
My question is why do they look so similar except for the shape of the copper? I would expect a dipole antenna to actually show two poles. Does the connector housing act as the other pole? If so then why is the monopole not a dipole as well?