射频功率晶体管研究

【作者】 郭本青；

【导师】 张庆中；

【作者基本信息】 电子科技大学 ， 微电子学与固体电子学， 2005， 硕士

【摘要】 针对高频功率晶体管的特点,提出采用多种技术、方法。综合这些方法研制了DCT260F 功率晶体管。这些方法包括: 1. 为解决可靠性问题,设计出过温保护电路,来取代通用的镇流电阻的做法,在温度上升至140oC,CMOS温度控制电路旁路掉射频功率管的大部分基极电流,电流不再集中,热量扩散,温度下降;当温度下降至87oC 时,CMOS 温度控制电路关闭旁路作用,射频功率晶体管回到正常的工作状态。来实现实时保护的同时又提高了器件高频优值的目的。2. 采用内匹配网络技术,设置输入、输出匹配网络,来保持增益和传输特性的平坦性;提高输出功率,和效率。降低反射系数,减少损耗。最终改善器件的高频特性,利于晶体管整体的功率传输。3. 使用Medici 对晶体管做关键的电学特性模拟,如:特征频率fT、击穿电压BVCBO、直流放大倍数β等;来验证各项设计指标。4. 利用反偏的PN 结做隔离岛,环绕CMOS 温度控制电路,并将其添加到器件内,制作在一个芯片衬底上,绘出完整的晶体管的版图。本文通过对DCT260F 的设计,提出了基于CMOS 温度控制电路的高可靠性、长使用寿命的射频晶体管的新设计思路,并成功完成前期仿真、版图工作,可望在后续工作中完成实用化,最终实现市场推广价值。更多还原

【Abstract】 Considering the character of high-freq. Power transistor, we adopt several methods. All of that can be expressed as follows. 1. To enhance the reliability of transistor, temperature protection circuit is designed, which replaces common ballasting resistor. circuit bypasses the most of base current of RF BJT when temperature rises to 140oC, and cuts off bypass function when temperature drops to 87oC. Therefore, RF BJT comes back to normal working state. All of that aims to realize a real time protection for transistor and improve the high-freq. character of device at the same time. 2. In order to keep gain smooth, enhance output power and efficiency, reduce reflect factor and attenuation, inner matching network both at input port and at output port is needed. That can finally improve high-freq character and facilitate the transfer of power. 3. To validate different target parameters, simulation work is done by using Medici around critical electrical parameter such as cutoff frequency fT, punch through voltage BVCBO, DC current gainβetc. 4. RF BJT cell and temperature control circuit are realized at one silicon die, which is insulated from each other by a back bias PN junction circle. Layout is also drawn. Take the design of DCT260F for example, a new method based on CMOS temperature control circuit to obtain high reliability and long life RF BJT is put forward. Computer simulation and layout is completed. With subsequent continuous work, ultimately that is coming to be commercialized and enter domestic and foreign market.更多还原