Systems and methods for extending the range of radio frequency identification (RFID) signal communications, including related sensing systems, are disclosed. In one embodiment, the system facilitates wireless communications between a RFID reader device and RFID transponder device and includes an extender circuit. The extender circuit includes a first tank circuit including a first inductor connected in parallel with a first capacitor between first and second nodes, and a second tank circuit including a second inductor connected in parallel with a second capacitor between third and fourth nodes. The extender circuit includes a first connection including a resistor, the first connection linking the first and third nodes, and a second connection between the second and fourth nodes, where the second and fourth nodes are at or substantially at a common voltage. In at least some additional systems, the extender circuit is implemented in combination with an RFID reader or transponder device.