一种新型有源预失真单片集成电路设计

Design of a New Active Predistorter MMIC

提出了一种适用于单片微波集成电路（MMIC）的有源预失真电路结构，给出了预失真单片电路的数学模型用来对设计参数进行优化选择，对要进行线性优化的功率放大器采用非线性方程来描述。基于这种电路结构和数学模型，设计了一款工作于19．6～21．2GHz的预失真单片电路。芯片采用GaAs0．15μm技术，测试结果显示：在加入有源预失真单片电路后，功率放大器（P-1为22dBm）在单音输出功率为16dBm时的三阶交调系数和五阶交调系数为-49dBc和-58dBc，分别改善了24dBc和15dBc，进一步验证了这种新型电路结构的可行性。

A predistortion linearizer well suited for monolithic-microwave integrated-circuit （MMIC） is presented in this paper. A mathematical model for the linearizer is given to optimize the various designed parameters in the specific implementation environment. The power amplifier to be linearized is described with nonlinear functions. A predistortion linearizer, which is based on this architecture and mathematical model and could operate in the 19.6~21.2 GHz band, em- ployed GaAs 0.15 μm technology and was implemented as a MMIC device. Measurement results show that when its 1 dB compression point is about 22 dBm, the IM3 and IM5 of the power am- plifier with the predistortion linearizer are -49 dBc and -58 dBc at 16 dBm output power （one- tone）, which have been improved by 24 dBc and 15 dBc, respectively. The feasibility of the novel circuit is thus verified.