Research On Microwave Arbitrary Waveform Generation Technology Based On Photon Assistance

Microwave photonic technology is an interdiscipline area that combines the two major technologies of microwave and photonics.It has attracted wide attention from researchers since its birth.The photonic technology based on optical fiber devices has advantages of large bandwidth,low loss,and anti-electromagnetic interference that create possibilities for the generation,transmission,and processing of broadband microwaves.The mature development of microwave technology creates the bridge of research on millimeter waves and even terahertz waves based on photonics.The development of microwave photonics technology has covered various fields of microwave research including microwave signal generation,transmission,and processing.Microwave photonic arbitrary waveforms are signal waveforms with frequencies(or bandwidth)in the microwave frequency band,including sine waves,triangular waveforms,square waveforms,sawtooth waveforms,linear chirp signals,ultra-wideband signals,and so on.These signal waveforms have significant applications in high-speed optical signal processing such as high-speed electro-optical switching,signal replication and wavelength conversion,microwave measurement technology,phased array radar,radio astronomy,and other fields.The photon-assisted generation scheme can generate high-speed,large bandwidth,large dynamic range microwave signals,and it can be combined with wavelength division multiplexing technology to build a multi-channel signal generation system.What's more,with the development of integrated photonics,the chip integration of the signal generation system can be realized.In this paper,we propose a triangular wave and square wave generation scheme based on dual-drive Mach-Zehnder modulator(DDMZM).Its feasibility and tunability are verified by experiments.Full-duty triangular waveforms and square waveforms with repetition frequencies of 5 GHz,8 GHz and 10 GHz were successfully generated.We calculated the root mean square error(RMSE)of the experimental value and the theoretical value respectively.Besides,we constructed an optoelectronic oscillator based on a dual laser structure,verified its tunability and generated a broadband tunable triangular wave with an OEO-based structure.The tuning range of OEO is from 4.38 GHz to 13.47 GHz.When the output frequency is 5 GHz,the phase noise performance is-112 d Bc/Hz@10 KHz.Finally,in order to meet the requirements of the phase array radar system,we conducted theoretical analysis and simulation on the scheme based on dual-polarization dual drive Mach-Zehnder modulator to generate sawtooth wave and triangular waveform.