Communication device

A communication device, comprising:

• a first ground element;
• a second ground element;
• a third ground element;
• a first signaling conductor, disposed between the first ground element and the second ground element;
• a second signaling conductor, disposed between the second ground element and the third ground element;
• a resonant circuit, wherein the first signaling conductor is coupled through the resonant circuit to the first ground element;
• and
• a dielectric substrate, having a first surface and a second surface opposite to each other, wherein the first ground element, the second ground element, the third ground element, the first signaling conductor, and the second signaling conductor are disposed on the first surface of the dielectric substrate;
• wherein the resonant circuit is configured to increase isolation between the first signaling conductor and the second signaling conductor in a target frequency band;
• wherein the resonant circuit comprises an inductive element and a capacitive element coupled in series;
• wherein the inductive element comprises:
• a first conductive pad, disposed on the first surface of the dielectric substrate;
• a second conductive pad, disposed on the first surface of the dielectric substrate;
• a third conductive pad, disposed on the second surface of the dielectric substrate;
• a fourth conductive pad, disposed on the second surface of the dielectric substrate, and coupled to the third conductive pad;
• a first connection via element, penetrating the dielectric substrate, and coupled between the first conductive pad and the third conductive pad;
• and
• a second connection via element, penetrating the dielectric substrate, and coupled between the second conductive pad and the fourth conductive pad;
• wherein each of the first conductive pad, the second conductive pad, the third conductive pad, and the fourth conductive pad substantially has a circular shape;
• wherein each of the first connection via element and the second connection via element substantially has a cylindrical shape;
• wherein a radius of the circular shape is substantially twice a radius of the cylindrical shape.