The planar inductive angular position sensor is popular in recent years for its low cost, high precision, and being well applicable in extreme environments. The decoding of the sensor’s output is focused to acquire angular position and velocity of objects. The sensor output signals need to be transformed into two signals: the sine and cosine signals by the demodulation module. Generally, the sine and cosine signals are unbalanced, i.e., they are not in the same amplitude and ninety degrees phase difference. The traditional decoding method synchronizes reference frame phaselocked loop (SRFPLL) can only be capable of acquiring correct angular position and velocity from balanced sine and cosine signals, which can not operate under unbalanced condition. In this work, a decoding method is proposed, termed double synchronous reference frame phaselocked loop (DSRFPLL), to acquire correct angular position and velocity under the unbalanced condition. Effectiveness of DSRFPLL decoding method is verified by simulation and experimental results.