Photonic Radar System Considerations for an Analog Optical Channel

In this work, an analog optical channel is analyzed regarding its features to work in the signal chain of an automotive FMCW photonic radar system which operates in the W-Band at 76.5 GHz. The paper presents the building blocks of the analog optical channel such as Mach-Zehnder-Modulator(MZM), Photodiode(PD) and Transimpedance-Amplifier(TIA). The transfer function, an equation for linearity and noise is derived for each component. Based on this a first order approximation of Third Order Harmonic Rejection (HR3) and Signal-to-Noise-Ratio(SNR) of the link is given. In the end an example link is plotted and it can be shown that the derived formulas led to good link performance for the analyzed link and satisfies the requirements for the radar system.