The Research Of Transient Electric Field Sensor Based On Electro-optic Modulator And Microstrip Antenna

In high power electromagnetic environment, transient pulse signal include nuclear electromagnetic pulses(NEMPs), lightning electromagnetic pulses(LEMPs) and high power microwaves(HPMs). The research object of this paper is the integrated optical waveguide electro-optic modulator and microstrip antenna. The sensor is designed and fabricated for time domain measurement of transient electric field. The design of sensor includes two parts of the structural parameters selected modulator electrodes and microstrip antenna structure.In the introduction, research status and development of integrated optical electric field sensor is introduced. By contrast, the electro-optic modulator can be used as sensors to realize the transient electric field measurement. The second chapter is the basic theory part. Through the integrated optical transient electric field sensing system, the related background knowledge of sensor be described. This part mainly analyzes the electro-optic modulator electrode, the external receiving antenna and transient pulse signal.By analyzing the basic characteristics of transient electric field, combined with the principle of electro-optic modulator modulation, and calculate the sensor theory model of external installation of sensing antenna.According to the traveling wave modulator electrode system, analyzes the influence of the center electrode, electrode gap width, thickness of the buffer layer and the electrode thickness on the characteristic impedance and effective refractive index. After comprehensive consideration, the paper completes the subsection optimization each part of the electrode system and obtained the dimensions of electrode. In device fabrication is completed, the bandwidth test indicates that 3dB bandwidth reaches 1GHz, which can be very good to cover the spectrum of the transient electric field. The main content of microstrip antenna simulation is the equivalent phase center stability analysis. Through the analysis of the antenna radiation pattern, 2# microstrip antenna phase center stability can be maintained in the range of 10~400 MHz. This is consistent with the transient pulse requirements to the receiving antennas.After completion of production, the paper tests the properties of the sensor. The asymmetric structure of electro-optic modulator operated in the linear region, when the laser wavelength is 1549.55 nm. The two sensors can maintain a relatively flat frequency response in the frequency below 300 MHz, and has a good linear dynamic range, minimum detectable signal 100 mV/m electric field. This article achieves all-optical measurement of transient electric field, by building integrated optical transient electric field sensing system. In the measurement of nanosecond pulsed electric field, space transient pulse is detected by 2# sensor. This shows that the sensor can realize the measurement of transient electric field, composed of electro-optic modulator and microstrip antenna. The sensor has a double meaning of research and engineering.