Patent ID: 8334728

Claim:
A high-frequency coupler comprising: ground; a coupling electrode configured to be supported so that the coupling electrode is placed opposite the ground and separately placed at a height from the ground, the height being negligible with respect to the wavelength of a high-frequency signal; a resonance section configured to increase electric current which enters the coupling electrode through a transmission path; and a stretchable and retractable connection section configured to connect a predetermined position on the coupling electrode and the resonance section; wherein an infinitesimal dipole is formed, the infinitesimal dipole including a line segment which connects the center of electric charge accumulated in the coupling electrode and the center of mirror electric charge accumulated in the ground, and the high-frequency signal is transmitted to another high-frequency coupler at a communication partner side, which is placed opposite the high-frequency coupler so that the angle θ between the direction of the infinitesimal dipole and the direction from the high-frequency coupler toward the other high-frequency coupler is nearly zero degrees.