Wide-band wave-transmitting/filtering radiation unit, shared-aperture antenna array, and communication device

A wide-band wave-transmitting/filtering radiation unit, comprising a radiation structure and a feed structure, wherein the radiation structure and the feed structure are coupled for feeding, whereby the radiation structure radiates low-frequency electromagnetic wave signals outward, the radiation structure comprises a radiator, and the radiator is loaded with a plurality of layers of surface periodic structures;

• when the radiation structure operates in a first mode, electromagnetic waves excited by a high-frequency radiation unit irradiate the radiation structure, the radiator and the plurality of layers of surface periodic structures on the radiation structure collectively form a non-resonant node spatial band-pass filter circuit with K resonant points and K null points, and K≥1;
• when the radiation structure operates in a second mode, low-frequency electromagnetic waves excite the radiation structure by means of the feed structure, units of the plurality of layers of surface periodic structures are excited by the radiator in a parallel manner to form an equivalent filter circuit;
• the radiator comprises four radiation arms, the four radiation arms are arranged on a baseboard, the four radiation arms are respectively a first radiation arm, a second radiation arm, a third radiation arm, and a fourth radiation arm, the first radiation arm and the third radiation arm constitute +45° polarization of a low-frequency radiation unit, and the second radiation arm and the fourth radiation arm constitute −45° polarization of the low-frequency radiation unit;
• and
• each radiation arm comprises a plurality of wave-transmitting/filtering units and a feed block, each wave-transmitting/filtering unit comprises two metal straight edges, a first open-circuit unit, and a second open-circuit unit, and the feed block is connected with the feed structure;
• the two metal straight edges are respectively arranged at a top layer and a bottom layer of the baseboard, the two metal straight edges are connected via a metal through hole, and the metal straight edges of the plurality of wave-transmitting/filtering units and the feed block are sequentially connected to form an annular polygon;
• and the first open-circuit unit and the second open-circuit unit are located at one side or two sides of the metal straight edges, and dual-band or wide-band wave transmission is achieved by controlling a resonant frequency of the first open-circuit unit and the second open-circuit unit.