Study Phase Modulation Or Intensity Modulation Of Instantaneous Frequency Microwave Photon Measurement System Based On

The development of information technology promotes the microwavecommunications and the rapid developments of optical fiber communication.Microwave communication can be emitted in any direction, easy to construct orreconstruction, and easy connection to mobile or portable equipment. Its cost fortransmission through the atmospheric is low with highly efficient frequencyutilization. The main problems lie in that a lot of losses caused by high frequencymicrowave transmission for long distance. This leads to the limited use of highfrequency extension. As a new subject, microwave photonics can realize theconversion between microwave signal and optical signal. Microwave communicationcan provide low cost mobile wireless connection mode, and optical fibercommunication provide low loss broadband connection and resistance toelectromagnetic interference. Microwave photonics combines microwavecommunication with fiber communication. It can realize radio frequency wave orhigher frequency band signal band-pass transmission without attenuation and nointerchannel interference. Compared with traditional microwave transmission, it hasa lot of advantages, such as small size, light weight, low cost, low loss, low dispersion,resistance to electromagnetic interference, high bandwidth, and large capacity, etc.Instantaneous microwave frequency measurement is one of the keytechnologies in the fields of electronic countermeasures and microwave detection. Itcan be used in radar signal and communication information intercepted andeavesdropping, electronic jamming and anti-interference, etc. Microwave frequencymeasurement system can overcome the problems of large size, high powerconsumption, being vulnerable to electromagnetic interference existed in thetraditional electronic microwave frequency measurement system. In this thesis wemainly study microwave frequency measurement system based on phase modulationor intensity modulation. We study different system schemes and their performances,such as frequency range, accuracy, etc. The major work and contributions are asfollows: 1. Using Optisystm and Matlab software, we study and analysize instantaneousmicrowave frequency measurement system based on single carrier input intensitymodulation, which realizes the measurement frequency range from0-12GHz.2. Putting forward system structure based on multicarrier input intensitymodulation, which realizes measurement frequency range within0-12GHz andprevents the measured frequency value from changing with inputting RF signalpower.3. Using sectional measurement, modulation of the phase of the instantaneousmicrowave frequency measurement method, the optimization measurementfrequency range and accuracy of measurement with the beneficial attempt. By theusing of input two carrier light wavelength, it shows that the measurementfrequency value relative to the specific frequency band is more representative. Weuse Optisystem and Matlab software to realize the system simulation design, whenmeasuring frequency range in6--11GHz, obtaining measurement accuracy value as0.5GHz; When measuring frequency range in11-15GHz, we obtain measurementaccuracy value as0.2GHz; When measuring frequency range in the15-GHz, weobtain measurement accuracy value as0.1GHz or so.4. Based on the combination of intensity modulation with phase modulation, wedesign the instantaneous microwave frequency measurement system and simulationby Optisystem and Matlab software. The simulation results show that withinfrequency range of0—15GHz, the accuracy value is0.3GHz. The simulation alsoverifies this scheme that can be realized without the limitation in the IMF schembased on intensity modulation induced by coaxial cable and it also solves the lowfrequency range measurement problem in the IMF scheme based on phasemodulation.