S波段宽带限幅低噪声放大器的设计

A Design of Wideband S-band Low Noise Amplifier with Limiter

本文描述了一款S波段小尺寸宽带高功率限幅低噪声放大器的设计及实现方法,采用混合集成电路方案、微组装工艺实现电路小型化,使用平衡式结构和负反馈电路改善宽带增益平坦度,使用半有源限幅结构实现高功率限幅要求。该设计在工作频带2~4 GHz内实现了噪声系数小于1.5dB,小信号增益大于37.5dB,增益平坦度小于0.8dB,输入输出驻波比小于1.5。该限幅低噪声放大器可承受脉冲功率350 W、脉宽3 ms、占空比30%的功率信号,外形尺寸24 mm×14 mm×5 mm。

This paper presents the design and fabricating techniques of a miniaturized wideband S-band low noise amplifier(LNA) with high power limiter. Based on the hybrid integrated circuit technology and micro-assembly technics, the circuit is miniaturized. The balanced structure and negative feedback techniques are adopted to improve the wideband gain flatness. The quasi-active limiter structure is adopted to fulfill the high power requirement. The designed LNA with limiter has a noise figure(NF) below 1.5 dB and the small signal gain higher than 37.5 dB with flatness less than 0.8 dB. The input and output VSWR is below 1.5. This design can handle pulsed power of 350 W peak power, 3 ms pulse width and 30% duty ratio. The dimension is only 24×14×5 mm.