Dual-frequency antenna

A dual-frequency antenna, comprising:

• a substrate, having a first surface and a second surface;
• a ground layer, located on the second surface;
• a plurality of signal feed portions, located on the first surface;
• at least one first radiation portion, located on the first surface;
• a plurality of second radiation portions, located on the first surface, wherein the plurality of second radiation portions and the at least one first radiation portion have different radiation frequency bands and serially connected in a staggered manner;
• a plurality of first signal transmission lines, located on the first surface, wherein one end of each of the first signal transmission lines is connected to one of the at least one first radiation portion, and the other end thereof is connected to one of the plurality of signal feed portions, and among the plurality of first signal transmission lines, two first signal transmission lines are connected to the same first radiation portion in a dual-polarized input manner;
• a plurality of second signal transmission lines, located on the first surface, wherein one end of each of the second signal transmission lines is connected to one of the plurality of second radiation portions, and the other end thereof is connected to one of the plurality of signal feed portions;
• a plurality of first filters, respectively disposed on the plurality of first signal transmission lines, wherein each of the first filters is electrically connected between one of the plurality of signal feed portions and one of the at least one first radiation portion;
• and
• a plurality of second filters, respectively disposed on the plurality of second signal transmission lines, wherein each of the second filters is electrically connected between one of the plurality of signal feed portions and one of the plurality of second radiation portions.