简介:A0.18lmCMOSlownoiseamplifier(LNA)byutilizingnoise-cancelingtechniquewasdesignedandimplementedinthispaper.Current-reuseandself-biastechniqueswereusedinthefirststagetoachieveinputmatchingandreducepowerconsumption.ThecoresizeoftheproposedCMOSLNAcircuitwithoutinductorwasonly128lm9226lm.ThemeasuredpowergainandnoisefigureoftheproposedLNAwere20.6and1.9dB,respectively.The3-dBbandwidthcoversfrequencyfrom0.1to1.2GHz.Whenthechipwasoperatedatasupplyvoltageof1.8V,itconsumed25.69mW.ThehighperformanceoftheproposedLNAmakesitsuitableformultistandardlow-costreceiverfront-endswithintheabovefrequencyrange.
简介:考虑了单位球面S^(n+1)(1)中具有常平均曲率H的超曲面M的拼脐问题.设A=∑i,j,kh(ijk)^2(λi+nH)^2,B=∑i,j,kh(ijk)^2(λi+nH)·(λj+nH),S=∑i(λi+nH)^2,其中h(ij)=λiδ(ij).利用拉格朗日方法,可以得到3(A-2B)关于S和|▽h|^2的估计,其中|▽h|^2=∑i,j,kh(ijk)^2.然后,利用该估计证明了:若M的第二基本形式的平方范数满足一定条件,则M一定等距于Clifford超曲面.因此,极小超曲面的拼脐结果被推广到具有常平均曲率的超曲面情形.