PPLN Electromagnetic Wave Radiation and Reception Research

• Main Authors: Chia-Wei Tsou, 鄒嘉威
• Other Authors: Yuan-Fang Chou
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/78752174377748883370

碩士 === 國立臺灣大學 === 機械工程學研究所 === 101 === In the year of 1888, Heinrich Hertz conducted the dipole antenna experiment to prove the authenticity of the electromagnetic wave theory of Maxwell (James Clerk Maxwell). Since the invention of the antenna, the application of electromagnetic waves ushers a new era. The basic principle of the antenna that it transforms the circuit current signal into a specific frequency of electromagnetic signals and then radiates the wave by specific orientation. On the other end, after receiving the electromagnetic signal, by the same physical principle, antenna transforms the wave into the current signal for circuit system use. So that messages of independent circuit systems can be transmitted by way of wireless link to each other, without any medium en route. In a nutshell, the antenna is a media device for transmission and reception of electromagnetic waves. There are various types of antenna today, but, so far ,no one has ever applied periodic modulation of piezoelectric materials as an antenna to send and receive electromagnetic signals. Purpose of this dissertation is to get rid of the tradition of the antenna pattern, but to use periodically poled lithium niobate to replace the conventional one. Periodically poled lithium niobate (PPLN) crystal has physical properties to receive and radiate electromagnetic waves. It has both types of propagation behavior of electromagnetic and mechanical waves. Such modulation crystal is also known as piezoelectric superlattices (PSLs). With this crystal wave propagation characteristics， EM wave reception and radiation phenomenon caused by polariton excitation at 13.56MHz frequency is the key of this new antenna theory. This experiment takes RFID (Radio Frequency Identification) systems as basic structure for test. Tag, one part of the RFID system, is portable data carrier. After decoding by ID Controller, Reader transmits electromagnetic signals and exchanges information with Tag. In general , to induct the electromagnetic wave from Reader , it needs to set up metal coils in Tag as antenna. The thesis develops periodic modulation lithium niobate chip, in which polariton excites at 13.56MHz frequency in behavior of mechanical and electromagnetic wave, and has series of full measurement on the chip physical properties, hoping to invent a new type of electromagnetic wave transceiver.