A Monolithic integrated phase locked-loop （PLL） with a low phase noise is proposed in this paper. Several techniques are utilized to improve the performance of the PLL which works at the milli- meter-wave band. The ...A Monolithic integrated phase locked-loop （PLL） with a low phase noise is proposed in this paper. Several techniques are utilized to improve the performance of the PLL which works at the milli- meter-wave band. The on-chip high-Q eoplanar waveguides （CPWs） are utilized in the resonant tank and the differential current amplifier with a resonator is used to realize the VCO. In the output buffer circuit, several stages of cascaded source-followers connect and differential amplifiers are adopted to improve the driving capability of the PLL＇ s output signals. An improved analog multiplier topology is also used in the PD circuit to improve the gain of the PD. The proposed PLL is realized with a 0.2p, m GaAs pseudomorphie high electron mobility transistor （PHEMT） process. At 10 kHz offset from the center frequency, the measured output phase noise of the PLL output is only -88.83dBc/Hz. The circuit exhibits a low root mean sauare （RMS） litter of 1.68Ds.展开更多
By utilizing poly（3-hexylthiophene） （P3HT） polymer nanowires with diameters of -15 nm as the vertical channel material, a polymer nanowire vertical transistor has been demonstrated for the first time. The P3HT nan...By utilizing poly（3-hexylthiophene） （P3HT） polymer nanowires with diameters of -15 nm as the vertical channel material, a polymer nanowire vertical transistor has been demonstrated for the first time. The P3HT nanowires were characterized by absorption spectroscopy and scanning electron microscopy. A saturated output current was created by increasing the thickness of the polymer layers between the electrodes through several spin-coating cycles of the polymer nanowires prepared in a marginal solvent. The carrier mobility was also increased through utilization of polymer nanowires with strong interchain interactions. By introducing a small hole injection barrier between the emitter and semiconducting polymer, an on/off current ratio of 1,500 was obtained. The operating voltage is less than 2 V.展开更多
An X-band AlGaN/GaN high-electron-mobility transistor (HEMT) on SiC substrate with high microwave power performances has been achieved. Its small-signal characteristics with a gate-length of 0.4 μm showed a unity cur...An X-band AlGaN/GaN high-electron-mobility transistor (HEMT) on SiC substrate with high microwave power performances has been achieved. Its small-signal characteristics with a gate-length of 0.4 μm showed a unity current gain cut-off frequency (fT) of 22 GHz and a maximum oscillation frequency (fmax) of 65 GHz. The GaN HEMT device with a gate width of 1 mm exhibited a continuous-wave saturated output power of 10.2 W and a linear gain of 14.8 dB at 8 GHz, and successfully achieved the power-added efficiency (PAE) as high as 69.2%, which is very suitable for X-band power applications.展开更多
基金Supported by the National Natural Science Foundation of China （No. 61106024, 60901012, 60976029） , the National High Technology Research and Development Program of China （No. 2011AA010301 ）, and the Science and Technology Program of Southeast University （No. K J2010402 ）.
文摘A Monolithic integrated phase locked-loop （PLL） with a low phase noise is proposed in this paper. Several techniques are utilized to improve the performance of the PLL which works at the milli- meter-wave band. The on-chip high-Q eoplanar waveguides （CPWs） are utilized in the resonant tank and the differential current amplifier with a resonator is used to realize the VCO. In the output buffer circuit, several stages of cascaded source-followers connect and differential amplifiers are adopted to improve the driving capability of the PLL＇ s output signals. An improved analog multiplier topology is also used in the PD circuit to improve the gain of the PD. The proposed PLL is realized with a 0.2p, m GaAs pseudomorphie high electron mobility transistor （PHEMT） process. At 10 kHz offset from the center frequency, the measured output phase noise of the PLL output is only -88.83dBc/Hz. The circuit exhibits a low root mean sauare （RMS） litter of 1.68Ds.
文摘By utilizing poly（3-hexylthiophene） （P3HT） polymer nanowires with diameters of -15 nm as the vertical channel material, a polymer nanowire vertical transistor has been demonstrated for the first time. The P3HT nanowires were characterized by absorption spectroscopy and scanning electron microscopy. A saturated output current was created by increasing the thickness of the polymer layers between the electrodes through several spin-coating cycles of the polymer nanowires prepared in a marginal solvent. The carrier mobility was also increased through utilization of polymer nanowires with strong interchain interactions. By introducing a small hole injection barrier between the emitter and semiconducting polymer, an on/off current ratio of 1,500 was obtained. The operating voltage is less than 2 V.
基金supported by the Knowledge Innovation Program of Chinese Academy of Sciences
文摘An X-band AlGaN/GaN high-electron-mobility transistor (HEMT) on SiC substrate with high microwave power performances has been achieved. Its small-signal characteristics with a gate-length of 0.4 μm showed a unity current gain cut-off frequency (fT) of 22 GHz and a maximum oscillation frequency (fmax) of 65 GHz. The GaN HEMT device with a gate width of 1 mm exhibited a continuous-wave saturated output power of 10.2 W and a linear gain of 14.8 dB at 8 GHz, and successfully achieved the power-added efficiency (PAE) as high as 69.2%, which is very suitable for X-band power applications.
