An accurate circuit model of the microwave small signal characteristics of AlGaAs/GaAs HBT (heterojunction bipolar transistor) is extremely useful for microwave linear applications of the device. This paper presents ...An accurate circuit model of the microwave small signal characteristics of AlGaAs/GaAs HBT (heterojunction bipolar transistor) is extremely useful for microwave linear applications of the device. This paper presents a small signal AlGaAs/GaAs HBT equivalent circuit, based on the DC characteristics and S parameter of the device. Using Volterra series, we have calculated the third order intermodulation distortion in a linear AlGaAs/GaAs HBT amplifier. The calculations are well concordant with the measurements from two tone signals intermodulation distortion test, and its excellent third order intermodulation performance shows that AlGaAs/GaAs HBT is a very attractive candidate for linear amplification.展开更多
This paper demonstrates the design and fabrication of a monolithic HBT power amplifier for TD-SCDMA cellu- lar phones that achieves high efficiency and linearity. The two-stage MMIC integrates the input matching circu...This paper demonstrates the design and fabrication of a monolithic HBT power amplifier for TD-SCDMA cellu- lar phones that achieves high efficiency and linearity. The two-stage MMIC integrates the input matching circuits,interstage matching circuits, and active bias circuits in a single chip with size as small as 0.91mm × 0.98mm. The amplifier obtains a power-added efficiency of 43% （15%） and a gain of 28.5dB （24dB） at the high and low operation mode under the 3.4V supply. In addition, the adjacent channel leakage power is below - 45dBc/- 56dBc and - 39dBc/- 50dBc at 1.6MHz/3.2MHz offset in low and high power output modes, respectively, with QPSK modulation. The MMIC offers the potential for low cost production due to small chip size, stable voltage supply, and high performance at the same time.展开更多
文摘An accurate circuit model of the microwave small signal characteristics of AlGaAs/GaAs HBT (heterojunction bipolar transistor) is extremely useful for microwave linear applications of the device. This paper presents a small signal AlGaAs/GaAs HBT equivalent circuit, based on the DC characteristics and S parameter of the device. Using Volterra series, we have calculated the third order intermodulation distortion in a linear AlGaAs/GaAs HBT amplifier. The calculations are well concordant with the measurements from two tone signals intermodulation distortion test, and its excellent third order intermodulation performance shows that AlGaAs/GaAs HBT is a very attractive candidate for linear amplification.
文摘This paper demonstrates the design and fabrication of a monolithic HBT power amplifier for TD-SCDMA cellu- lar phones that achieves high efficiency and linearity. The two-stage MMIC integrates the input matching circuits,interstage matching circuits, and active bias circuits in a single chip with size as small as 0.91mm × 0.98mm. The amplifier obtains a power-added efficiency of 43% （15%） and a gain of 28.5dB （24dB） at the high and low operation mode under the 3.4V supply. In addition, the adjacent channel leakage power is below - 45dBc/- 56dBc and - 39dBc/- 50dBc at 1.6MHz/3.2MHz offset in low and high power output modes, respectively, with QPSK modulation. The MMIC offers the potential for low cost production due to small chip size, stable voltage supply, and high performance at the same time.
