首页 chap4-3fN

chap4-3fN

举报
开通vip

chap4-3fN High Order ?-? modulator 1. Basic Blocks with Integrator and Differentiator 2. Stability Consideration with 1st ?-? modulator 3. Transfer Function 4. Realization by Accumulator 5. Example 1 6. Example 2 7. Improvement 8. Case Design for DCS-1800 ???...

chap4-3fN
High Order ?-? modulator 1. Basic Blocks with Integrator and Differentiator 2. Stability Consideration with 1st ?-? modulator 3. Transfer Function 4. Realization by Accumulator 5. Example 1 6. Example 2 7. Improvement 8. Case Design for DCS-1800 ???-? modulator 1-Z-1 1 1-Z-1 1 + Z-1 + + input qa ??? ??? ??? ??? - 21 )1( −−+= zqInputOutput a ???-? modulator 31 )1( −−+= zqInputOutput a input 1-Z-1 1 1-Z-1 1 + Z-1 + + output qa 1-Z-1 1+ ??? ??? ??? ??? ??? - - 1. Integrator is replaced by the first order ?-? modulator, Which is more stable. 2. The extra quantization noise should be suppressed or minimized. 3. The Block of MASH-1-1-1 (Multi-stage Noise Shaping) is proposed. MASH-1-1-1 ???-? modulator MASH-1-1-1 1-Z-1 1 ++ Z-1 + 1-Z-1 1 1-Z-1 1 + + + Z-1 Z-1 1-Z-1 1-Z-1 + ++ + .f[Z] qa1[Z] - qa1[Z] - qa2[Z] qa2[Z] qa3[Z] N[Z]N1[Z] N2[Z] N3[Z] N1[z]= .f[z]+[1-z-1]qa1 N2[z]= -qa1+[1-z-1]qa2 N3[z]=-qa2+[1-z-1]qa3 N[z]=N1[z]+(1-z-1) N2[z]+ (1-z-1)2 N3[z] X1 1 11 . −−= zqfX a ???-? modulator N1[z]= .f[z]+[1-z-1]qa1 N2[z]= -qa1+[1-z-1]qa2 N3[z]=-qa2+[1-z-1]qa3 Nf[z]=N1[z]+[1-z-1] N2[z]+ [1-z-1]2 N3[z] =.f[z]+ [1-z-1]3 qa3 =.f[z]+qe3 Transfer Function )( 2 reff fj ez π−=231 )1()( −−= zfH ? 3 2 3 2 )1()1( refref f fj f fj ee ππ −−⋅−= 3 )2cos(22     −= reff fπ )(sin2 33 reff fπ= ref qa f fS ⋅=12 1)(3    ⋅= ⋅= refref qafqe f f f fSfHS π6 2 )(3 sin 3 16 )()( PSD of Phase Error refe f fref fN f fS πθ 6 2 sin)(3 16 )( ⋅= 3 2 ' )( qe ref S Nf f fS e ⋅    ⋅=θ )(sin )'(3 8 2 1)( 6 2 ref ref f f fN f SfL e π θ ⋅= = Hz rad 2 2 refff ≤ ???? ?????? ????????????????? i ref ref f f fN f fL 2 2 )(sin2)'(24 )(     ⋅= π Hz rad 2 2 refff ≤ i=?? 40dB/dec ???-? modulator by Accumulator X Y X+Y Z-1 X Y X+Y Z-1 X Y X+Y Z-1 Z-1 Z-1 ++ .f[Z] N[Z] N1[Z] N2[Z] N3[Z] ???-??????? Discuss: ???? Order II: N-1, N, N+1, N+2 Order III: N-3, N-2, N-1, N, N+1, N+2, N+3, N+4 PFD LPF VCO ????? fref fout K ??????? Example 1:???-? modulator ???? ???? 25 7 2 39000010 +=Fraction Example 2:Worse Case(I) ???? 25 21 2 2=Fraction ???? )2,( 2 M M KGCD p ∝ M??????????GCD???????? ??????? Improvement 25 21 2 12 +=Fraction Example for DCSExample for DCS--18001800 PFD LPF VCO ?P fref Multi-mode divider 3? ∆−Σ fOUT K Prescaler FPGA3 25 P??30 ?????3MHz N.f?19?20 Fout=1710?1800MHz ???K= 390000107 + MHzMHzFout 86.1737330) 2 3900001019( 25 7 =⋅    ⋅++=
本文档为【chap4-3fN】,请使用软件OFFICE或WPS软件打开。作品中的文字与图均可以修改和编辑, 图片更改请在作品中右键图片并更换,文字修改请直接点击文字进行修改,也可以新增和删除文档中的内容。
该文档来自用户分享,如有侵权行为请发邮件ishare@vip.sina.com联系网站客服,我们会及时删除。
[版权声明] 本站所有资料为用户分享产生,若发现您的权利被侵害,请联系客服邮件isharekefu@iask.cn,我们尽快处理。
本作品所展示的图片、画像、字体、音乐的版权可能需版权方额外授权,请谨慎使用。
网站提供的党政主题相关内容(国旗、国徽、党徽..)目的在于配合国家政策宣传,仅限个人学习分享使用,禁止用于任何广告和商用目的。
下载需要: 免费 已有0 人下载
最新资料
资料动态
专题动态
is_404487
暂无简介~
格式:pdf
大小:278KB
软件:PDF阅读器
页数:0
分类:互联网
上传时间:2012-07-07
浏览量:6