A two-stage monolithic low noise amplifier is developed for satellite communication applications,using a 0.5μm enhancement PHEMT technology. The on-chip matched amplifier employs lumped elements to reduce the circuit...A two-stage monolithic low noise amplifier is developed for satellite communication applications,using a 0.5μm enhancement PHEMT technology. The on-chip matched amplifier employs lumped elements to reduce the circuit size, and shows a 5012 noise figure less than 0.9dB, gain greater than 26dB, and return loss less than - 10dB in the S-C band range of 3.5 to 4. 3GHz. The noise figure obtained here is the best result ever reported to date of an MMIC LNA with a gain of more than 20dB for the S-C band frequency range. It is attributed to the low noise performance of the enhancement PHEMT transistor and minimized parasitic resistance of the input match network by a common series source inductor and a unique divided resistance at the drain.展开更多
A three-stage MMIC power amplifier operating from 6to 18GHz is fabricated using 0.25μm A1GaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor（PHEMT）.The amplifier isfully monolithic,with all matching,bi...A three-stage MMIC power amplifier operating from 6to 18GHz is fabricated using 0.25μm A1GaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor（PHEMT）.The amplifier isfully monolithic,with all matching,biasing,and DC block circuitry included on the chip.Thepower amplifier has an average power gain of 19dB over 6～18GHz.At operation frequenciesfrom 6 to 18GHz,the output power is above 33.3dBm,and the maximum output power of the MMICis 34.7dBm at 10Ghz.The input return loss is less than-10db and the out-put return is lessthan-6dB over operating frequency.This power amplifier has,to our knowledge,the best powergain flatness reported at C-X-Ku-band applications.展开更多
To find a design method for 3D active multichannel silicon microelectrode, a microstructure of active neural recording system is presented, where two 2D probes, two integrated circuits and two spacers are microassembl...To find a design method for 3D active multichannel silicon microelectrode, a microstructure of active neural recording system is presented, where two 2D probes, two integrated circuits and two spacers are microassembled on a 5 mm×7 mm silicon platform, and 32 sites neural signals can be operated simultaneously. A theoretical model for measuring the neural signal by the silicon microelectrode is proposed based on the structure and fabrication process of a single-shank probe. The method of determining the dimensional parameters of the probe shank is discussed in the following three aspects, i.e. the structures of pallium and endocranium, coupled interconnecters noise, and strength characteristic of neural probe. The design criterion is to minimize the size of the neural probe as well as that the probe has enough stiffness to pierce the endocranium. The on-chip unity-gain bandpass amplifier has an overall gain of 42 dB over a bandwidth from 60 Hz to 10 kHz; and the DC-baseline stability circuit is of high input resistance above 30 MΩ to guarantee a cutoff frequency below 100 Hz. The circuit works in stimulating or recording modes. The conversion of the modes depends on the stimulating control signal.展开更多
文摘A two-stage monolithic low noise amplifier is developed for satellite communication applications,using a 0.5μm enhancement PHEMT technology. The on-chip matched amplifier employs lumped elements to reduce the circuit size, and shows a 5012 noise figure less than 0.9dB, gain greater than 26dB, and return loss less than - 10dB in the S-C band range of 3.5 to 4. 3GHz. The noise figure obtained here is the best result ever reported to date of an MMIC LNA with a gain of more than 20dB for the S-C band frequency range. It is attributed to the low noise performance of the enhancement PHEMT transistor and minimized parasitic resistance of the input match network by a common series source inductor and a unique divided resistance at the drain.
文摘A three-stage MMIC power amplifier operating from 6to 18GHz is fabricated using 0.25μm A1GaAs/InGaAs/GaAs pseudomorphic high electron mobility transistor（PHEMT）.The amplifier isfully monolithic,with all matching,biasing,and DC block circuitry included on the chip.Thepower amplifier has an average power gain of 19dB over 6～18GHz.At operation frequenciesfrom 6 to 18GHz,the output power is above 33.3dBm,and the maximum output power of the MMICis 34.7dBm at 10Ghz.The input return loss is less than-10db and the out-put return is lessthan-6dB over operating frequency.This power amplifier has,to our knowledge,the best powergain flatness reported at C-X-Ku-band applications.
基金Supported by Tianjin Municipal Science and Technology Commission(No. 05YFSYSF01700).
文摘To find a design method for 3D active multichannel silicon microelectrode, a microstructure of active neural recording system is presented, where two 2D probes, two integrated circuits and two spacers are microassembled on a 5 mm×7 mm silicon platform, and 32 sites neural signals can be operated simultaneously. A theoretical model for measuring the neural signal by the silicon microelectrode is proposed based on the structure and fabrication process of a single-shank probe. The method of determining the dimensional parameters of the probe shank is discussed in the following three aspects, i.e. the structures of pallium and endocranium, coupled interconnecters noise, and strength characteristic of neural probe. The design criterion is to minimize the size of the neural probe as well as that the probe has enough stiffness to pierce the endocranium. The on-chip unity-gain bandpass amplifier has an overall gain of 42 dB over a bandwidth from 60 Hz to 10 kHz; and the DC-baseline stability circuit is of high input resistance above 30 MΩ to guarantee a cutoff frequency below 100 Hz. The circuit works in stimulating or recording modes. The conversion of the modes depends on the stimulating control signal.
