Research On Millimeter-wave System Based On Forward-modulation And N-DSB Modulation

Radio-over-Fiber(Ro F)technology is a new communication technology,which combines the optical fiber communication and microwave communication.Ro F technology uses the optical fiber to replace the cable to transmit the millimeter wave signal.The technology has a low cost,simple system structure.It provides a new solution for the next generation of Internet multimedia demand.Ro F technology uses a plurality of base stations sharing a central station.The central station structure is very complex,the base station is very simple.The system is easy to operate,install and maintain.Millimeter wave(mm-wave)has a direct impact on the application of the whole Ro F system,therefore optical mm-wave technology is the key technology of Ro F system,and has become a hot research topic in Ro F system.The main work and research results are as follows:1.This paper proposes the high quality of the 120 GHz optical mm-wave technology.The technology has carried on the theoretical analysis and simulation verification.This system can generate 120 GHz mm-wave signal through appropriate design of RF driven phase shift and DC bias.The results show that this technology can use the low frequency vibration signal generating high-frequency mm-wave signal.This mm-wave has good transmission performance.This system uses Mach-Zehnder Modulators(MZM)series connection through the ingenious design section modulator bias voltage and driven RF phase shift can generate mm-wave signal with phase noise free between lasers.It has potential applications in the high frequency of the vibration generated.2.In this paper,a new type of Double-Sideband modulation technique(N-DSB),which is composed of two MZM.The modulation technique has higher modulation efficiency.In theoretical analysis and simulation results,N-DSB achieved 2-th order and above the high order component was completely suppressed through cleverly design the phase shift of each phase shifter and the bias voltage of MZM.The mm-wave signal generated by the modulation technique has better anti dispersion performance and can effectively improve the transmission performance of Ro F system.3.This paper researches a 60 GHz mm-wave system based on N-DSB modulator.This principle of the system is similar to the high quality 120 GHz optical mm-wave system,thus there is no phase noise of the 60 GHz mm-wave.In this system,the N-DSB modulation technology can suppress high orders and greatly reduce the mm-wave signal error rate.At the same time,the system can reduce the dispersion effect by using the Fiber Bragg Grating(FBG)and the N-DSB.The mm-wave signal is pure.The system can generate dual channel transmission signals and greatly reduce the cost.