Communication apparatus and communication system

A communication system comprising:

• a first communication apparatus and a second communication apparatus, the first communication apparatus including a differential transmission path formed of a first electrode and a second electrode, disposed on a first surface of a substrate, to perform wireless communication with the second communication apparatus through an electromagnetic field coupling;
• and
• a transmission circuit connected to one end of the first electrode and one end of the second electrode and configured to transmit a signal to the differential transmission path;
• a first resistor connected to an opposite end of the first electrode;
• a second resistor connected to an opposite end of the second electrode;
• and
• a common mode filter connected to the differential transmission path and disposed on a second surface of the substrate,
• wherein the first electrode and the second electrode are each formed in a substantially arc shape about a predetermined axis, and an arc length of the first electrode and an arc length of the second electrode are different from each other.

A communication apparatus comprising:

• a differential transmission path including a first electrode and a second electrode to perform wireless communication with another communication apparatus through an electromagnetic field coupling;
• a transmission circuit connected to one end of the first electrode and one end of the second electrode and configured to transmit a signal to the differential transmission path;
• a first resistor connected to an opposite end of the first electrode;
• a second resistor connected to an opposite end of the second electrode;
• and
• a common mode filter connected between the one end and the opposite end of the first electrode and between the one end and the opposite end of the second electrode,
• wherein the first electrode and the second electrode are each formed in a substantially arc shape about a predetermined axis, and an arc length of the first electrode and an arc length of the second electrode are different from each other.