超宽带发射机的射频前端设计

【作者】 高稳元；

【导师】 寇戈；

【作者基本信息】 南京理工大学 ， 通信与信息系统， 2012， 硕士

【摘要】 随着无线通信技术的发展,当下移动通信中的带宽已经不能满足多媒体传输的需求,3G网络应运而生。但是由于3G在发达国家运营的效果并不理想,因此各大电信设备上都提出了组建LTE(Long Term Evolution)网络。又因为GSM和WCDMA等2G、3G业务仍处于盈利状态,所以提出了包含GSM、WCDMA和TD-LTE等协议的超宽带多模式收发射机的设计。本课题即基于这种多模式收发机系统,对发射部分的射频前端进行了研究和设计。本文首先分析了发射机射频架构的优缺点,选择了合适的架构；接着研究了发射机射频设计的理论基础,包括调制精度、邻信道选择性、杂散辐射、发射功率和自动增益控制等重要指标；然后根据选择的架构和设计指标的要求,采用电子开关和射频声表滤波器协作的方式来完成发射机多模式的设计,利用阻抗匹配来实现宽带平坦度的要求,并对关键电路进行了仿真；最后,选择合适的芯片搭建单元电路,在此基础上完成发射机链路的设计并进行调测。实际调测结果表明,系统的各项指标在不同模式、不同载波下都达到预期的效果,验证了本设计方案的可行性。更多还原

【Abstract】 With the development of wireless communication, the bandwidth of the current mobile communication has been unable to meet the needs of multimedia transmission, the 3G networks was born at the right moment. Although 3G networks have been developed to solve this problem, due to the bad effect of 3G networks in developed countries, the major telecom equipment companies have decided to build LTE (Long Term Evolution) networks. As GSM and WCDMA business remained profitable, a multi-mode (including GSM, WCDMA and TD-LTE) ultra-wide-band transceiver was proposed.Based on the UWB (Ultra-wide Bandwidth) multi-mode transceiver, the RF front-end of the transmitter was designed in this issue. First, advantages and disadvantages of the RF front-end structure were analyzed and then proper architecture was selected. Second, the main theory of transmitter design, including the modulation accuracy, adjacent channel selectivity, spurious radiation, the transmission power, automatic gain control and other important parameters, was studied. Third, according to the selected architecture and design requirements, the electronic switches and RF SAW filters were used in a collaborative manner to complete the target of multi-mode, and impedance matching was used to meet the required flatness of broadband, and after that the key circuits were simulated. Finally, appropriate chips were selected to build circuits, and based on these circuits, the transmitter system was developed and tested.According to the actual adjust and test results, the parameters satisfied the demands in different modes and different carriers, and so that this design was available.更多还原