Microwave signals can be photonically generated by a quantum dot, passively mode locked laser. The main advantages of using this microwave source configuration are the small size of the device (approximately 8000×300 microns at a frequency of 5GHz), the stable signal output with low phase noise, the reconfigurability (tunable output power and frequency by controlling the dc biasing) and high optical to electrical conversion efficiency. Although some work on the subject has been published in the past, a detailed description of the microwave properties of the QDMLL is missing. In order for the QDMLL to be used as a microwave source, its microwave functionality need to be studied. In this current work, a QDMLL is characterized in terms of its output microwave impedance, the maximum output microwave power, the resonant frequency, the linewidth of the signal, the phase noise as well as the optical to electrical power convertion efficiency.