Two photonic millimeter-wave synthesizers based upon optical heterodyning will be presented. The first synthesizer features a coaxial output port (W1) and can be continuously tuned from DC to 110GHz offering a 6dB roll off for the entire frequency span and a maximum output power of -3.23dBm. An approach with a rectangular waveguide output port (WR10) for operation exceeding the W-band (70-115GHz) providing a 3dB roll off and a maximum output power of 0dBm will be further presented.