共查询到4条相似文献,搜索用时 0 毫秒
1.
《Microelectronics Journal》2014,45(6):740-750
A low power frequency synthesizer for WLAN applications is proposed in this paper. The NMOS transistor-feedback voltage controlled oscillator (VCO) is designed for the purpose of decreasing phase noise. TSPC frequency divider is designed for widening the frequency range with keeping low the power consumption. The phase frequency detector (PFD) with XOR delay cell is designed to have the low blind and dead zone, also for neutralizing the charge pump (CP) output currents; the high gain operational amplifier and miller capacitors are applied to the circuit. The frequency synthesizer is simulated in 0.18 µm CMOS technology while it works at 1.8 V supply voltage. The VCO has a phase noise of −136 dBc/Hz at 1 MHz offset. It has 10.2% tuning range. With existence of a frequency divider in the frequency synthesizer loop the output frequency of the VCO can be divided into the maximum ratio of 18. It is considered that the power consumption of the frequency synthesizer is 4 mW and the chip area is 10,400 µm2. 相似文献
2.
Semiconductors - For obtaining multicomponent III–V solid solutions, the vapor-phase methods such as the chloride–hydride epitaxy, the epitaxy from organometallic compounds, and the... 相似文献
3.
Yu. N. Nozdrin A. V. Okomel’kov A. P. Kotkov A. N. Moiseev N. D. Grishnova 《Semiconductors》2004,38(12):1374-1377
Stimulated emission of radiation from CdxHg1?xTe samples pumped by a Nd:YAG laser at temperature T≈77 K is obtained. Both spontaneous and stimulated emission is observed for the wavelengths λ in the range 3300–3600 nm. Experimental emission spectra are presented. The special features of the spectra and the possible applications of the structures are discussed. 相似文献
4.
We report a series-connected small molecule tandem photovoltaic cell utilizing two donors with complementary photovoltaic characteristics, lead phthalocyanine (PbPc) in the front subcell and boron subphthalocyanine chloride (SubPc) in the back subcell, to achieve both near infrared (NIR) response up to 1 μm and high open-circuit voltage (VOC) of more than 1.5 V in the same device. We find that the C60 layer thickness in the front subcell has a critical impact on the overall optical structure and photovoltaic performance of the tandem device. By combining transfer matrix calculations with subcell-selective spectral measurements, we are able to tune the optical field distribution inside the active layers and increase the photocurrent outputs from both subcells, leading to EQE > 30% over the wavelength range 400 nm < λ < 900 nm. This optimized tandem cell exhibits JSC = (5.5 ± 0.1) mA/cm2, fill factor = 0.54, VOC = 1.53 V, and a power conversion efficiency of (4.5 ± 0.2)%. 相似文献