An RF signal offset circuit using a half wavelength transmission line is provided. The RF signal offset circuit includes an RF transformer having an input coil and an output coil. The input coil has first and second input ports. The output coil has first and second output ports. One of the output ports is grounded. A half wavelength transmission line having first and second ends is connected in parallel to the input coil of the RF transformer. First and second resistance devices are respectively connected between the first end of the transmission line and the first input port of the RF transformer and between the second end of the transmission line and the second input port of the RF transformer.