Linearization Techniques Of Radio Frequency Power Amplifiers

With the rapid development of wireless communication techniques, linear modulation, wideband communications are becoming more and more popular .Now, in high frequency communications, several channels can be dealt with together. Since the envelope of sideband(SSB) modulated signal fluctuates, these signals summed together generate unwanted intermodulation distortion products in a nonlinear Radio Frequency (RF) Power Amplifier(PA).So it is necessary to use linearization technique to reduce the adjacent channel interface. Digital predistortion is a widely used linearization technique because of its unique advantage. The main studying of this dissertation is about HF communication techniques, digital predistortion linearizer based on Look-up Table(LUT) technology ,simulation of the digital predistortion system and at last, realization techniques are discussed. The main work and valuable results in this dissertation are as follows.1 Present the SSB modulation and some characters of HF communication.2 Modeling the nonlinear RF power amplifier, analysis the reason of its intermodulation.3 Simulation of digital predistortion techniques.4 Realization of this system in HF communication., deal with some difficult problems.