Systems and methods for determining antenna impedance

Systems and methods for determining antenna impedance are provided. The method includes generating, by a signal source coupled to the antenna, a radio frequency (RF) signal, applying the RF signal to a directional coupler, and mixing, by a first mixer, a first signal from the directional coupler with a signal, wherein the first signal corresponds to a reflected power from the antenna. The method further includes mixing, by a second mixer, a second signal with the signal, wherein the second signal is offset from the first signal by ninety degrees. The method further includes outputting, by a first lower pass filter (LPF) coupled to an output of the first mixer, a real part of a reflection coefficient of the antenna and outputting, by a second lower pass filter (LPF) coupled to an output of the second mixer, an imaginary part of the reflection coefficient.