基于噪声抵消的有源匹配SiGeHBT低噪声放大器设计

摘要

Based on Jazz 0.35 μm SiGe process, a SiGe HBT low-noise amplifier (LNA) for 2G, 3G and WIMAX application is presented. Taking advantage of the characteristics of low input impedance of common base transistor and low output impedance of common collector transistor, active match in input and output is achieved by selecting the structure and bias current of transistors. The chip area with pad is only 0.33 mm × 0.31 mm because the large area inductor is not used. Because the noise figure of the common base transistor is higher than that of the common emitter transistor, the adoption of noise cancellation reduces the noise introduced from the common base transistor. In the bandwidth of 0.6 - 3 GHz, the LNA shows that the gain is 17.8 - 19.2 dB, gain flatness is ±0.9 dB, the input and output match well, input and output reflections (S11 and S22) are both less than -10 dB, and the LNA is unconditionally stable in the whole band.%基于Jazz0．35μmSiGe工艺，设计了一种满足2G、3G和WIMAX标准的有源匹配SiGeHBT低噪声放大器．利用共基极晶体管输入阻抗小和共集电极晶体管输出阻抗较小的特点，通过选取晶体管的结构和偏置电流，实现了输入、输出有源阻抗匹配．由于未采用占芯片面积大的电感，减少了芯片面积，芯片面积（含焊盘）仅为0．33mmX0．31mm；由于共基极晶体管的噪声系数比共射极晶体管的噪声系数高，采用噪声抵消结构减少了其引入噪声．低噪声放大器在（0．6～3）GHz工作频带内，增益为17．8～19．2dB，增益平坦度为±0．7dB；有源输入、输出匹配良好；在整个频段内，无条件稳定．