The Design And Improvement Of Circuit And Antenna Based On CDMA Phones

Modern Mobile Communication Technology started in 1920's During these 80 years, Mobile Communication Technology have been changed from analog to digital. Personal communication and integrated service are the main ideals of people about mobile communication. We know that frequency is the life of mobile communication. It blocks the advance of mobile communication that the more and more service requests and the limited frequency resource are conflicted. CDMA technic is a way to resolve this problem. People pay more attention to CDMA now. It becomes a key technic to realize personal communication. When we developed the GSI product and software radio technic, we can get a better CDMA telecommunication system.This article discusses one new CDMA IP multimedia mobile phone baseband solution. This IP phone successfully improves the original design of the shortcomings of IP telephone and becomes more powerful. So it achieves more stable performance of the design requirements.The key technologies in IP phone is the design of the base-band circuit, RF module and antenna performance. Firstly, this paper introduces the basic conception of the IP phone and its application in Wireless communication systems, and also gives us the basic theory of CDMA communication. Secondly, the paper introduces the base-band circuits, radio frequency modules, and antenna system architecture of the IP phone ,then gives the overall design of them. Moreover, the paper carries out a detailed and comprehensive introduction of the sub-module design, the debugging process and the measures to resolve the issue, including specific design and methods of the main circuit of the digital baseband, analog baseband circuits, RF modules, as well as the antenna.The follow-up work of the paper is the production of the circuit board as well as the whole debugging work. At the same time , the various sub-modules need to be further optimized, so as to achieve better results.