In this paper, a tunable microwave photonic filter with one complex coefficient is proposed and experimentally demonstrated. The complex coefficient is generated using a tunable optical RF phase shifter that consists of a semiconductor optical amplifier (SOA) and a tunable band-pass filter (TBPF). The phase of the RF signal is shifted by the differentiation process in semiconductor optical amplifier (SOA) where both Cross-Phase Modulation (XPM) and Cross-Gain Modulation (XGM) effects are exploited simultaneously. A two-tap photonic microwave filter with one tunable complex coefficient and a tuning range of a full free spectral range (FSR), is experimentally demonstrated.© (2010) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.