Synthesis of Dual Cross LFM Signals Based on Technologies of Microwave Photonics

This article proposes and shows a model demonstration of the photon approach to the generation of microwave oscillations with dual cross linear frequency modulation based on tandem amplitude-phase modulation using a series-connected two amplitude and one phase Mach-Zehnder modulators. In the proposed approach, the baseband oscillation with a single LFM is fed to the first amplitude Mach-Zehnder modulator, and the microwave carrier to the second. When these two modulators are shifted to the linear part of the modulation characteristic, dual cross LFM microwave oscillations are generated on an optical carrier, the level of which can be adjusted by switching the received radiation in the phase Mach-Zehnder modulator from zero to the LFM oscillation level. A theoretical analysis is carried out, which is then model tested by an experiment in the Optiwave System software. The creation of microwave oscillations with dual cross LFM with a carrier equal to 1 GHz and tunable bandwidth up to 600 MHz is shown. Microwave oscillations with dual cross LFM can be used in radar systems to improve their Doppler and range resolution of moving objects or in the same purposes applicated for different media boarders in ionospheric positioning dynamic (moving) systems and combined high-intensity microwave photonic systems for gas condensate extraction, etc.