Self-transmitting and self-receiving coil and working method thereof

The invention relates to a self-transmitting and self-receiving coil which comprises a transmission line structure and a reference layer switching circuit, one end of the transmission line structure is connected with a radio frequency signal input end through a first T/R switch, and the other end of the transmission line structure is grounded through a second T/R switch and a matched resistor; one end of the transmission line structure is also connected with a second radio frequency signal output end through a fourth T/R switch, and the other end of the transmission line structure is connected with a first radio frequency signal output end through a third T/R switch; the transmission line structure comprises a coil winding, and a reference layer is arranged outside the coil winding. A dielectric layer is arranged between the reference layer and the coil winding, and the dielectric layer is used for controlling characteristic impedance between the reference layer and the coil winding, so that the characteristi