Transmission and reception of radio waves require antennas. In providing gateways to transmission and reception of radio signals, antennas play important roles both at the base station and mobile terminal. Though, higher transmit power and greater receiver sensitivity can improve radio link quality and reliability, the regulatory authorities place a ceiling to the transmit power in order to limit interference to other users. The receiver sensitivity is determined by manufacturing costs; receivers with greater sensitivity are much more expensive. Thus, good antenna design can potentially deliver substantial improvement in the system performance.