A waveguide structure comprising: a first conductive plane; a second conductive plane; and a plurality of unit structures, wherein the second conductive plane is disposed opposite to the first conductive plane, and each of the unit structures comprises: a first transmission line (4A, 104); a second transmission line (4B, 204B); and a conductive via (5, 105), wherein the first transmission line (4A, 104) and the second transmission line (4B, 204B) are disposed in a same layer or different layers, wherein the same layer is opposite to the second conductive plane, and the different layers are opposite to the second conductive plane, and the first transmission line (4A, 104) comprises: a first end; and a second end, wherein the first end is an open end, and the second end is electrically connected to the first conductive plane through the conductive via (5, 105), and the second transmission line (4B, 204B) comprises: a third end; and a fourth end; wherein the third end is an open end, and the fourth end is electrically connected to the first conductive plane through the conductive via (5, 105), characterized in that the first transmission line (4A, 104) and the second transmission line (4B, 204B) have different lengths. a first conductive plane; a second conductive plane; and a plurality of unit structures, wherein the second conductive plane is disposed opposite to the first conductive plane, and each of the unit structures comprises: a first transmission line (4A, 104); a second transmission line (4B, 204B); and a conductive via (5, 105), wherein the first transmission line (4A, 104) and the second transmission line (4B, 204B) are disposed in a same layer or different layers, wherein the same layer is opposite to the second conductive plane, and the different layers are opposite to the second conductive plane, and the first transmission line (4A, 104) comprises: a first end; and a second end, wherein the first end is an open end, and the second end is electrically connected to the first conductive plane through the conductive via (5, 105), and the second transmission line (4B, 204B) comprises: a third end; and a fourth end; wherein the third end is an open end, and the fourth end is electrically connected to the first conductive plane through the conductive via (5, 105), characterized in that the first transmission line (4A, 104) and the second transmission line (4B, 204B) have different lengths. the second conductive plane is disposed opposite to the first conductive plane, and each of the unit structures comprises: a first transmission line (4A, 104); a second transmission line (4B, 204B); and a conductive via (5, 105), wherein a first transmission line (4A, 104); a second transmission line (4B, 204B); and a conductive via (5, 105), wherein the first transmission line (4A, 104) and the second transmission line (4B, 204B) are disposed in a same layer or different layers, wherein the same layer is opposite to the second conductive plane, and the different layers are opposite to the second conductive plane, and the first transmission line (4A, 104) comprises: a first end; and a second end, wherein the first end is an open end, and the second end is electrically connected to the first conductive plane through the conductive via (5, 105), and the second transmission line (4B, 204B) comprises: a third end; and a fourth end; wherein the third end is an open end, and the fourth end is electrically connected to the first conductive plane through the conductive via (5, 105), characterized in that the first transmission line (4A, 104) and the second transmission line (4B, 204B) have different lengths. disposed in a same layer or different layers, wherein the same layer is opposite to the second conductive plane, and the different layers are opposite to the second conductive plane, and the first transmission line (4A, 104) comprises: a first end; and a second end, wherein the first end is an open end, and the second end is electrically connected to the first conductive plane through the conductive via (5, 105), and a first end; and a second end, wherein the first end is an open end, and the second end is electrically connected to the first conductive plane through the conductive via (5, 105), and the first end is an open end, and the second end is electrically connected to the first conductive plane through the conductive via (5, 105), and the second transmission line (4B, 204B) comprises: a third end; and a fourth end; wherein the third end is an open end, and the fourth end is electrically connected to the first conductive plane through the conductive via (5, 105), characterized in that the first transmission line (4A, 104) and the second transmission line (4B, 204B) have different lengths. a third end; and a fourth end; wherein the third end is an open end, and the fourth end is electrically connected to the first conductive plane through the conductive via (5, 105), characterized in that the first transmission line (4A, 104) and the second transmission line (4B, 204B) have different lengths. the third end is an open end, and the fourth end is electrically connected to the first conductive plane through the conductive via (5, 105), characterized in that the first transmission line (4A, 104) and the second transmission line (4B, 204B) have different lengths.