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
Ultralong phosphorescent materials have numerous applications across biological imaging, lightemitting devices, X-ray detection and anti-counterfeiting. Triplet-state molecular phosphorescence typically accompanies th...Ultralong phosphorescent materials have numerous applications across biological imaging, lightemitting devices, X-ray detection and anti-counterfeiting. Triplet-state molecular phosphorescence typically accompanies the singlet-state fluorescence during photoluminescence, and it is still difficult to achieve direct triplet photoemission as ultralong room temperature phosphorescence(RTP). Here, we have designed Zn-IMDC(IMDC, 4,5-imidazoledicarboxylic acid) and Cd-IMDC, two-dimensional(2D)hydrogen-bond organized metal–organic crystalline microsheets that exhibit rarely direct ultralong RTP upon UV excitation, benefiting from the appropriate heavy-atom effect and multiple triplet energy levels. The excitation-dependent and thermally stimulated ultralong phosphorescence endow the metal–organic systems great opportunities for information safety application and temperature-gated afterglow emission. The well-defined 2D microsheets present color-tunable and anisotropic optical waveguides under different excitation and temperature conditions, providing an effective way to obtain intelligent RTP-based photonic systems at the micro-and nano-scales.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 the Beijing Municipal Natural Science Foundation(JQ20003)the National Natural Science Foundation of China(21771021,21822501,and 22061130206)+3 种基金the Fok Ying-Tong Education Foundation(171008)the Measurements Fund of Beijing Normal Universitythe State Key Laboratory of Heavy Oil Processing。
文摘Ultralong phosphorescent materials have numerous applications across biological imaging, lightemitting devices, X-ray detection and anti-counterfeiting. Triplet-state molecular phosphorescence typically accompanies the singlet-state fluorescence during photoluminescence, and it is still difficult to achieve direct triplet photoemission as ultralong room temperature phosphorescence(RTP). Here, we have designed Zn-IMDC(IMDC, 4,5-imidazoledicarboxylic acid) and Cd-IMDC, two-dimensional(2D)hydrogen-bond organized metal–organic crystalline microsheets that exhibit rarely direct ultralong RTP upon UV excitation, benefiting from the appropriate heavy-atom effect and multiple triplet energy levels. The excitation-dependent and thermally stimulated ultralong phosphorescence endow the metal–organic systems great opportunities for information safety application and temperature-gated afterglow emission. The well-defined 2D microsheets present color-tunable and anisotropic optical waveguides under different excitation and temperature conditions, providing an effective way to obtain intelligent RTP-based photonic systems at the micro-and nano-scales.
