In this paper, we propose a narrowband FSK transceiver scheme, which enables WPDT link to transmit power efficiently when transmitting data. Using this approach, the power transfer efficiency (PTE) and the power delivered to the load (PDL) were measured to be 51.92% and 92.42 mW, respectively. With carrier frequencies of 3.952 and 4.516 MHz, the WPDT link we have implemented can transmit data at a rate of 564.48 kbps, with a 5.35-µH transmitter coil and a 0.7-µH receiver coil. The transmitter SoC is fabricated in a 0.18-µm CMOS technology and occupies 2 mm2. We also designed the corresponding demodulation circuit, of which power consumption is 8.49 uW. Our approach is expected to provide a new communication solution for biomedical implants.