The Research On The Key Technology Of Integrated Polymer RF Phase Shifter

Optical phased array technology is the modern radar technology that combines both microwave technology and photonics technology for controlling the scanning beam of the antenna arrays. This technology realized the advantage complementary between microwave technology and photonics technology, so it has unique advantages in upgrading radar scanning speed,working frequency,instantaneous bandwidth and scanning accuracy and plays an important role in satellite communications,radio astronomy,space and air control. Integrated Radio Frequency (RP) phase shifter is widely concerned and researched as the key device of controlling beam-forming, as for the domestic research of this device is still in the state of theory, only a separation device constructed phase shifter is occasionally reported, while in the abroad the researcher have already begun the study of integrated devices. Our research is just based on this background. In this dissertation ,we have introduced a new integrated polymer RF phase shifter that shift the phase of RF signal optically. On the base of our laboratory conditions, the dissertation is focused on the key technology in the design and fabrication of integrated polymer RF phase shifter. The main works are as follows:1. The development of organic polymer, the research history and current situation about polymer optical waveguide devices are reviewed,the current situation of integrated RF phase shifter is introduced.2. The theory of electro-optic effect of polymer is investigated. As we all know, the design of the phase shifter suffers from a lack of phase shift linearity and a substantial amount of power variation as the phase is tuned. A new integrated polymer RF phase shifter that shift the phase of RF signal optically is introduced.3. Polymer optical waveguide is an important component in polymer RF phase shifter. The waveguide parameters of the device are optimized by the Variational Effective Index Method, the Finite Difference Beam Propagation Method (FD-BPM), Operator Expansion Beam Propagation Method, and Wide Angle Finite Difference Beam Propagation Method. 4. Based on total internal reflection, a novel asymmetric Y-branch waveguide is proposed in this dissertation, in which the center between the input waveguide and the two branch waveguides is shifted to a small distance A x, and the branching ratio can be controlled by changing A x.5. Another key technology is how to design electrodes structure. The author writes much programme based on the conformal mapping method to simulate electrodes structure of modulators in detail.6. The major processing steps of polymer waveguide are studied. The prototype of polymer M-Z waveguide and asymmetric Y-branch waveguide are obtained. The electro-optic coefficient of polymer after polarization is 50pm/v.7. Waveguide propagation attenuation measuring system is designed based on a refined measurement method - Liquid Coupling Method. A system for measuring the electro-optic coefficient based on the Simple Reflection Method is introduced. A waveguide sample is tested with the Prism Coupling Method and the refractive index is obtained.8. The coupling of fiber and waveguide is a key step of device packaging and it directly affects the inserting loss of the device. In this dissertation, the coupling loss between optical fiber and polymeric rib waveguide are analyzed with Wide Angle Finite Difference Beam Propagation Method and Effective Index Method. The experimental platform is set up.