A Narrowband Four-Quadrant Electro-Optical Mixer for Microwave Photonics

This letter presents a narrowband (NB) four-quadrant electro-optical (EO) mixer for microwave photonic applications. The proposed NB architecture is optimized to multiply an optical signal with an electrical signal without an intermediate transimpedance amplifier (TIA). Within this work, the main mixer characteristics like EO conversion gain and linearity of the proposed NB EO mixer architecture are derived analytically and validated by means of a printed circuit board (PCB) demonstrator operating in the 2.45 GHz industrial, scientific, and medical (ISM) band. The proposed NB mixer architecture can be integrated monolithically into modern photonic CMOS and BiCMOS technologies, which offer higher frequencies of operation for the proposed NB EO mixer. In the PCB demonstrator, the frequency of operation is limited by the transistors and the photodiode (PD) cut off frequency.