共查询到20条相似文献,搜索用时 78 毫秒
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射频功放是线性技术中的一项研究项目,关系到射频功率放大器的应用效果。射频功放中的核心是数字预失真技术,深入研究数字预失真技术,保障其在射频功放中的应用效果,最主要的是满足射频功率放大器的需求,体现数字预失真技术的优势,因此,本文通过对数字预失真技术进行研究,分析其在射频功放中的应用。 相似文献
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Clesca B. Bousselet P. Auge J. Blondel J.P. Fevrier H. 《Photonics Technology Letters, IEEE》1994,6(11):1318-1320
Within analog video transmission systems, optical amplifiers have to display simultaneously good noise and output power performance because of the very stringent carrier-to-noise ratio requirements imposed by the AM-VSB modulation format. We show, theoretically and experimentally, that properly designed forward 1480-nm pumped erbium-doped fiber amplifiers can deliver +16 dBm saturated output power with noise parameter (nsp/Cx) as low as 3.5dB. These amplifiers do not exhibit significant degradation of their noise performance when the input powers are as large as +3 dBm. These characteristics make 1480-nm pumped amplifiers suitable for AM-VSB transmission systems 相似文献
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50-GHz SiGe HBT distributed amplifiers employing constant-k and m-derived filter sections 总被引:4,自引:0,他引:4
This paper describes two single-ended three-stage SiGe HBT distributed amplifiers employing constant-k filter sections, m-derived filter sections, and a metal or a deep-trench ground plane in the artificial transmission lines. The distributed amplifiers exhibit a measured passband of 100 MHz-50 GHz; they have a small die size (1.0/spl times/1.1 mm/sup 2/) and low power consumption (125 mW). The measured results demonstrate that distributed amplifiers in SiGe can be competitive with those in III-V processes. 相似文献
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Gain saturation behavior in L-band EDFAs 总被引:1,自引:0,他引:1
The gain saturation behavior of an L-band erbium-doped fiber amplifier is investigated. Experimental results show that amplifiers configured to operate in the L-band exhibit decidedly different saturation behavior compared to what is observed in C-band amplifiers. It is shown that the gain can vary by as much as 2.3 dB. Results suggest that the unique saturation behavior observed in the L-band is due, in part, to backward traveling amplified spontaneous emission power 相似文献
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Two novel CMOS single-ended amplifiers are presented. Suitable for switched-capacitor-filter designs, they exhibit high gain and bandwidth as well as high PSRR, low power and small size. 相似文献
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A practical method is introduced, to design single-stage broadband microwave amplifiers with mixed lumped and distributed elements via modeling the reflectance data obtained from lumped-element input and output matching network prototypes. The same transducer power gain level is obtained by using less number of lumped-elements in the mixed-element amplifier than that of the lumped-element amplifier prototype. A mixed-element amplifier design is presented, to exhibit the utilization of the method. It is expected that the method will be employed, to design microwave amplifiers for broadband communication systems. 相似文献
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Amplification of linear modulation schemes, (which exhibit fluctuating envelopes), by high power amplifiers invariably leads to the generation of distortion and intermodulation products. Recent theoretical work has suggested that a complex gain predistorter may be employed to linearize a nonlinear power amplifier. The authors present experimental results demonstrating that a reduction in out-of-band spectra in excess of 20 dB may be achieved by employing digital feedback and a complex gain predistorter 相似文献
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This paper describes a study of the performance of various configurations for placing multiple optical amplifiers in a typical coherent ultrashort light pulse code-division multiple access (CULP-CDMA) communication system using the additive noise model. For this study, a comprehensive performance analysis was developed that takes into account multiple-access noise, noise due to optical amplifiers, and thermal noise using the saddle-point approximation technique. Prior to obtaining the overall system performance, the input/output statistical models for different elements of the system such as encoders/decoders, star coupler, and optical amplifiers were obtained. Performance comparisons between an ideal and lossless quantum-limited case and a typical CULP-CDMA with various losses exhibit more than 30 dB more power requirement to obtain the same bit-error rate (BER). Considering the saturation effect of optical amplifiers, this paper discusses an algorithm for amplifiers' gain setting in various stages of the network in order to overcome the nonlinear effects on signal modulation in optical amplifiers. Finally, using this algorithm, various configurations of multiple optical amplifiers in CULP-CDMA are discussed and the rules for the required optimum number of amplifiers are shown with their corresponding optimum locations to be implemented along the CULP-CDMA system. 相似文献
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基于近几年的文献报道,综述了110GHz以上固态功率放大器的现状和电路结构。归纳了每个固态放大器的工作频率、制作工艺、最大输出功率(Psal)、最大输出的压缩增益、小信号增益、1dB压缩点增益(P-),功率附加效率(PAE)、带宽等指标。对每个固态放大器的电路结构进行了总结,讨论了这些电路结构在太赫兹频段的应用。并根据ITRS的文献展望了未来固态晶体管的发展。最后讨论了未来太赫兹固态功率放大器集成到太赫兹数模系统的方式。 相似文献
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L. Colace V. SorianelloM. Romagnoli L. SocciG. Assanto 《Microelectronic Engineering》2011,88(4):514-517
We report on the fabrication and operation of optical power monitors monolithically integrated on silicon-on-insulator optical chips. The devices consist of near-infrared waveguide pn heterojunction photodiodes in evaporated germanium. The low temperature growth of Ge is compatible with silicon waveguide technology. The photodetectors exhibit typical responsivities of 10-30 mA/W; the power monitors are used with front-end trans-impedance amplifiers based on commercially available operational amplifiers and can operate with optical signals as small as 10 nW, with errors below 0.2% and 2% at 1 and 0.1 μW, respectively. 相似文献
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Yo-Chuol Ho Ki-Hong Kim Floyd B.A. Wann C. Yuan Taur Lagnado I. O K.K. 《Solid-State Circuits, IEEE Journal of》1998,33(12):2066-2073
Four- and 13-GHz tuned amplifiers have been implemented in a partially scaled 0.1-1 μm CMOS technology on bulk, silicon-on-insulator (SOI), and silicon-on-sapphire (SOS) substrates. The 4-GHz bulk, SOI, and SOS amplifiers exhibit forward gains of 14, 11, and 12.5 dB and Fmin's of 4.5 (bulk) and 3.5 db (SOS). The 13-GHz SOS and SOI amplifiers exhibit gains of 15 and 5.3 dB and Funn's of 4.9 and 7.8 dB. The 4-GHz bulk amplifier has the highest resonant frequency among reported bulk CMOS amplifiers, while the 13-GHz SOS and SOI amplifiers are the first in a CMOS technology to have tuned frequencies greater than 10 GHz. These and other measurement results suggest that it may be possible to implement 20-GHz tuned amplifiers in a fully scaled 0.1-1 μm CMOS process 相似文献