Research Of Multimode Reconfigurable LNA For GPS, Beidou And TD-LTE-A

With the development of wireless communication, more and more wireless communication standards and applications come into people’s life. This requires the receivers to support multi-modes and multi-bands with lower hardware cost, and the design of low noise amplifier (LNA) is becoming more and more important for its special location. Traditional way to realize multimode and multiband is by using switches to choose a proper LNA from the LNA array. This method is commonly used for its good performance and easy realization, but the trend is towards a maximum hardware reuse. With the increase of communication standards, this method is becoming more and more unsuitable, a reconfigurable LNA for GPS, Beidou and TD-LTE-A is proposed in this paper.First, the basic theory of the LNA design is investigated in this paper, it mainly includes noise theory, matching theory and LNA’s specifications. Then, the four common used LNA structures is analyzed, their benefits and drawbacks are summarized. Based on these analyze, the source inductive degeneration architecture is adopted, and switched inductances at gate electrode and drain electrode are used to realize reconfiguration of the LNA. Finally, the simulation results are presented of the proposed LNA, and simple analysis is made about these simulation results.The proposed LNA works at GPS L1band, Beidou B1and B2bands, and TD-LTE-A D band, and it works well under these bands with a maximum gain of larger than20dB, a noise factor (NF) less than5dB, and an IIP3of larger than-10dBm, it dissipates as less as15mW with a1.8V source supply. The post-simulation results are similar to the pre-simulation results, and the proposed LNA achieves the goals well.