Dual-band antenna design for GPS and UMTS applications

In this paper, a new design of an integrated antenna for the applications of GPS and UMTS is proposed. A broadband monopolar patch antenna with conical radiation patterns [5] is used as a radiating element for UMTS operation, and its radiating patch is placed at the inner-slot area of a circular-polarized (CP) square-ring microstrip element for GPS operation. Consequently, the two antenna elements of the proposed design can be fabricated on a single printed circuit board. In order to obtain the isolation of more than 20 dB between the two input ports, a 3rd Order Butterworth low pass filter (LPF) is designed and placed at the input port of the GPS antenna element. Details of the proposed design and obtained results are presented and discussed.