一种2.4GHz全集成SiGe BiCMOS功率放大器

A 2.4 GHz Fully-integrated SiGe BiCMOS Power Amplifier

针对2.4 GHz 802.11 b/g无线局域网(WLAN)的应用,该文设计了一种单片全集成的射频功率放大器(PA)。由于在自适应偏置电路中采用异质结晶体管(HBT)和电容构成的简单结构提高PA的线性度,因此不增加PA的直流功耗、插损和芯片面积。在基极偏置的DC通路中采用电阻负反馈实现温度稳定功能,有效避免热崩溃的同时不引起射频损耗。采用了GRACE 0.18μm SiGe BiCMOS工艺流片,芯片面积为1.56 mm2,实现了包括所有偏置电路和匹配电路的片上全集成。测试结果表明,在2.4-2.5 GHz工作频段,PA的小信号增益S 21达23 dB,输入回波损耗S 11小于-15 dB。PA的1 dB输出压缩点的线性输出功率为19.6 dBm,功率附加效率为20%,功率增益为22 dB。

A fully-integrated SiGe BiCMOS Power Amplifier （PA） is presented for the 2.4 GHz 802.11b/g wireless LAN application. The linearization is improved by the simple HBT-capacitor structure in the adaptively biasing circuit, without additional DC power consumption, chip area and insertion loss. The temperature stabilization is achieved in the HBT＇s DC base biasing path by negative feed back. This scheme prevents effectively thermal runaway and causes no RF power penalty. The proposed power amplifier is fabricated in 0.18 ~m SiGe BiCMOS process and the chip area is 1.56 mm2 including all the biasing and matching circuits. The measurement results indicate that, in band of 2.4-2.5 GHz, this PA gets the small-signal gain Szof 23 dB, and the input return loss S11 of less than -15 dB. The proposed PA achieves the linear output power of 19.6 dBm, the Power Added Efficiency （PAE） of 20%, and the power gain of 22 dB at the output 1 dB compression point. Key words： SiGe BiCMOS; Power Amplifier （PA）; dly-integrated; Adaptively biasing