Voltage divider biasing common emitter amplifier is one of the core contents in analog circuit curriculum, and almost all of traditional textbooks apply approximate calculation method to estimate all characteristic pa...Voltage divider biasing common emitter amplifier is one of the core contents in analog circuit curriculum, and almost all of traditional textbooks apply approximate calculation method to estimate all characteristic parameters. In calculating quiescent point, transistor base current is generally ignored to get the approximate base potential and emitter current, then other operating parameters, and AC small signal parameters can be acquired. The main purpose of this paper is to compare traditional and Thevenin equivalent methods and to get the difference of the two methods. A Formula is given to calculate the error of the traditional method. Example calculating reveals that the traditional method can generate an error about 10%, and even severe for small signal amplifier with higher quiescent point.展开更多
In this paper we report on a novel structure of a 4H-SiC bipolar junction transistor with a double base epilayer that is continuously grown. The measured dc common-emitter current gain is 16.8 at Ic = 28.6 mA （Jc = 1...In this paper we report on a novel structure of a 4H-SiC bipolar junction transistor with a double base epilayer that is continuously grown. The measured dc common-emitter current gain is 16.8 at Ic = 28.6 mA （Jc = 183.4 A/cm2）, and it increases with the collector current density increasing. The specific on-state resistance （Rsp-on） is 32.3 mΩ.cm2 and the open-base breakdown voltage reaches 410 V. The emitter N-type specific contact resistance and N＋ emitter layer sheet resistance are 1.7× 10-3 Ω.cm2 and 150 Ω/□, respectively.展开更多
Design and fabrication of a Ka-band voltage-controlled oscillator（VCO） using commercially available 1-μm GaAs heterojunction bipolar transistor technology is presented.A fully differential common-emitter configurat...Design and fabrication of a Ka-band voltage-controlled oscillator（VCO） using commercially available 1-μm GaAs heterojunction bipolar transistor technology is presented.A fully differential common-emitter configuration with a symmetric capacitance with a symmetric inductance tank structure is employed to reduce the phase noise of the VCO,and a novel π-feedback network is applied to compensate for the 180° phase shift.The on-wafer test shows that the VCO exhibits a phase noise of-96.47 dBc/Hz at a 1 MHz offset and presents a tuning range from 28.312 to 28.695 GHz.The overall dc current consumption of the VCO is 18 mA with a supply voltage of-6 V.The chip area of the VCO is 0.7×0.7 mm^2.展开更多
文摘Voltage divider biasing common emitter amplifier is one of the core contents in analog circuit curriculum, and almost all of traditional textbooks apply approximate calculation method to estimate all characteristic parameters. In calculating quiescent point, transistor base current is generally ignored to get the approximate base potential and emitter current, then other operating parameters, and AC small signal parameters can be acquired. The main purpose of this paper is to compare traditional and Thevenin equivalent methods and to get the difference of the two methods. A Formula is given to calculate the error of the traditional method. Example calculating reveals that the traditional method can generate an error about 10%, and even severe for small signal amplifier with higher quiescent point.
基金Project supported by the National Natural Science Foundation of China (Grant No. 60876061)the National Defense Key Laboratory Foundation from Nanjing National Defense Key Laboratory of Nanjing Electronic Devices Institute,China (GrantNo. 20090C1403)
文摘In this paper we report on a novel structure of a 4H-SiC bipolar junction transistor with a double base epilayer that is continuously grown. The measured dc common-emitter current gain is 16.8 at Ic = 28.6 mA （Jc = 183.4 A/cm2）, and it increases with the collector current density increasing. The specific on-state resistance （Rsp-on） is 32.3 mΩ.cm2 and the open-base breakdown voltage reaches 410 V. The emitter N-type specific contact resistance and N＋ emitter layer sheet resistance are 1.7× 10-3 Ω.cm2 and 150 Ω/□, respectively.
基金Project supported by the National Key Basic Research Program of China(No.2010CB327505)the Advanced Research Project(No.51308xxxx06)the Advanced Research Foundation(No.9140A08xxxx11DZ111)
文摘Design and fabrication of a Ka-band voltage-controlled oscillator（VCO） using commercially available 1-μm GaAs heterojunction bipolar transistor technology is presented.A fully differential common-emitter configuration with a symmetric capacitance with a symmetric inductance tank structure is employed to reduce the phase noise of the VCO,and a novel π-feedback network is applied to compensate for the 180° phase shift.The on-wafer test shows that the VCO exhibits a phase noise of-96.47 dBc/Hz at a 1 MHz offset and presents a tuning range from 28.312 to 28.695 GHz.The overall dc current consumption of the VCO is 18 mA with a supply voltage of-6 V.The chip area of the VCO is 0.7×0.7 mm^2.
