Abstract
The objective of this paper is to present a quad-band antenna for handset application includes the effects of a metallic ring and a hand. We show that it is necessary to co-design the antenna and the ring together, since the metal ring has a significant influence on the performance of the antenna. The effect of the hand on the efficiency of the composite antenna and metal ring is investigated and it is shown that the radiation efficiency of the phone degrades rather significantly when the phone is gripped by the hand.