Read more
Master's Thesis from the year 2017 in the subject Physics - Technical Physics, grade: 82, Charles Darwin University (School of Engineering and Information Technology), course: Electrical and Electronics Engineering, language: English, abstract: The focus is given on millimeter/micro wave signal generation based on external modulators. The working principle and modulation characteristics of Mach-Zehnder modulators (MZM) are introduced. Literature review is presented on generating millimeter/micro wave signals with 4-, 6-, and 8-times frequency multiplication based on cascaded MZMs or dual-parallel MZMs (DPMZMs). A novel scheme to optically generate a microwave signal with 10-times frequency multiplication is proposed. The proposed scheme is based on two DPMZMs and a polarizer. It does not require electrical phase shifters with specified degrees, which are needed in the conventional 10 times frequency multiplication structure. Simulation is conducted to evaluate the performance of the proposed scheme. When a 1 GHz RF drive signal turns into two DPMZMs with a 35 dB extinction ratio, the proposed 10 times frequency multiplier with an optical sideband suppression ratio (OSSR) higher than 25 dB can be obtained. A 10 GHz mm-wave with an RF spurious suppression ratio (RFSSR) over 16 dB is generated. A frequency quadrupling scheme based on a DPMZM is experimentally demonstrated. With a 3 GHz RF drive signal, an OSSR higher than 8 dB is obtained and a 12 GHz mm-wave is generated with an RFSSR over 11 dB.
