Rf Front-end Design, Ultra-wideband Transmitter

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.