Patent attributes
A circularly polarized patch antenna assembly having a relatively compact volume includes a substrate, a radiation metal piece, a grounded metal piece and a signal-inputting body. A plurality of frequency down-conversion metal pieces in a form of elongate stripe extends from four sides of the grounded metal piece, thereby to reduce the resonant frequency. The frequency down-conversion metal pieces are adhered on the side face of the substrate, so that the frequency down-conversion metal piece on one side face is arranged diagonally with respect to the frequency down-conversion metal piece on the opposite side face. When the resonant frequency of the antenna is to be reduced, the position and the area of the frequency down-conversion metal piece can be adjusted but the increased area of the frequency down-conversion metal piece cannot be larger than a half area of the side face of the substrate. Alternatively, the length of the frequency down-conversion metal piece can be increased.
