the electrode is located close to {TAIL ~ a portion} where the electric field intensity generated by {HEAD ~ the electromagnetic waves} becomes strong in the antenna when the electromagnetic waves are fed to the antenna 
the electrode is located close to { TAIL ~ a portion } where the electric field intensity generated by { HEAD ~ the electromagnetic waves } becomes strong in the antenna when the electromagnetic waves are fed to the antenna
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH