Substrate antenna

A substrate antenna comprising:

• a loop-like first joint pattern, one spot of which is divided, the first joint pattern being formed in a one-side substrate surface of a substrate comprised of a dielectric material;
• antenna elements that configure a first antenna, the antenna elements being respectively connected to both ends of the first joint pattern at a position where the first joint pattern is divided, to transmit and receive transmission and reception signals from a feeding point and an earth point formed on the substrate;
• a second joint pattern having approximately a same loop-like shape as the first joint pattern, one spot of which is divided, the second joint pattern being formed in the other-side substrate surface of the substrate at a position opposite to the first joint pattern, wherein the first joint pattern and the second joint pattern are aligned with each other in their divided positions so as to be electrostatic capacitively-coupled via an electrostatic capacitance of the substrate and magnetic inductively-coupled;
• and
• antenna elements that configure a second antenna, the antenna elements being respectively connected to both ends of the second joint pattern at a position where the second joint pattern is divided,
• wherein the first antenna and the second antenna are capable of transmitting and receiving transmission and reception signals from the feeding point and the earth point shared in common.