The article focuses on designing a wearable rectenna to harvest low-power RF energy for a biomedical device pasted on human body. The wearable textile material we selected for on-body application is cordura fabric. The textile rectenna is designed at the WiFi frequency band, 2.45 GHz to harvest RF energy. The rectenna has a rectifier and a patch antenna which is linear-polarized. The rectifier is a single-stage full-wave Greinacher rectifier where we added a radio frequency choke (RFC) to increase the output voltage. The output DC voltage of the rectenna can achieve 2.2 volts when the RF power is swept from -40 dBm to 0 dBm. It has excellent performance as pasted on the human body. The maximum output voltage of 2×2 array rectenna is about 1.05 volts as the power transferring distance is 150 cm in the indoor of WiFi environment.