基于最小噪声匹配的低噪放-天线一体化电路

LNA-Antenna Integrated Circuit Based on Minimum Noise Matching

传统的接收端天线与低噪声放大器(LNA)级联,通常需将天线输出阻抗与LNA的输入阻抗均匹配到50Ω,为此引入的匹配电路不仅占用了较大的电路尺寸,而且额外引入插入和失配等损耗。为消除匹配网络,本文提出一种基于ATF-54143晶体管的低噪放-天线一体化电路,基于最小噪声条件下将天线的阻抗与LNA晶体管的输入阻抗实现匹配。该方案通过直接优化微带天线的阻抗实现与LNA晶体管的宽带匹配,不使用任何形式的输入阻抗匹配网络来构建有源集成天线,从而克服了传统设计存在的问题和不足。实验测试表明,在2~3 GHz的带宽内,噪声系数(NF)较传统级联设计都有改善,且最大改善可达0.38 dB(较传统设计NF降低16%)。

The traditional receiver antenna is cascaded with a low-noise amplifier(LNA), usually it is necessary to match the antenna output impedance and the input impedance of the LNA to 50 Ω. The matching circuit introduced for this not only occupies a larger circuit size, and additional losses such as insertion and mismatch are introduced. In order to eliminate the matching network, this paper proposes a LNA-antenna integrated circuit based on the ATF-54143 transistor, which matches the impedance of the antenna with the input impedance of the LNA transistor under the minimum noise condition. This solution directly optimizes the impedance of the microstrip antenna to achieve broadband matching with the LNA transistor, and does not use any form of input impedance matching network to construct an active integrated antenna, thereby overcoming the problems and shortcomings of traditional designs. Experimental tests show that in the bandwidth of 2-3 GHz, the noise figure(NF) is improved compared with the traditional cascade design, and the maximum improvement can reach 0.38 dB(16% lower than the traditional design NF).