A 96 Mbit/sec, 15.5 pj/bit 16-QAM Modulator for UHF Backscatter Communication#

A 96 Mbit/sec, 15.5 pj/bit 16-QAM Modulator for UHF Backscatter Communication#!"#$%&"'()'*+,-%./'0%""+#$'!)'1#23,45.' 6'."#$%&")"+,-%.7589#)#58':/'6'-%"")&#23,45.7589#)#58':' ;#<")',='>4#?"&@?%4'%35'A,-<8"#&'>3B@3##&@3B' ;89#'C3@D#&.@"2' ;8&+%-/'EA'C!F' F<&@4'G/'HIJH'

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Conventional View of Sensor Data Links#! P,&'"&%5@"@,3%4'4,$T<,$#&'5#D@?#.'%35'.#3.,&./' 5%"%'8<4@39'@.'?,."42'%35'+%.'5&@D#3'4,$T<,$#&'.#3.,&'&#.#%&?+)' ''!"#$%&'%()*'+#,-*)+%.'#.,#$/'$.-#'/+0.-1#-/$/*-)2#2*$#*33-/$$/3#+2/# 4-.56/7#.,#/'/-&89/:)%/')8;#!"#$%"#&'()'(*+!&,#-#./(-0*(1%2-(-0%-( 2,$!3-%-#,.(#4($%.'(,"5*"4(,1($%/.#-35*(&*44(*+!*.4#6*(-0%.( "%5#,(2,$$3.#2%-#,.<#=2%$#).74>+*+%.'#?$<#).77>'%)*+%.'#+-*3/9.@#2*$#2*3#*#+-/7/'3.>$#%'A>/')/#5.+2#.'#*6&.-%+27#3/$%&'#*$#0/66# *$#.'#$/'$.-#'/+0.-1#46*+,.-7#3/$%&'<B# U0%"+#&'#")'F4/'VC4"&%TS,$'K,$#&';%"%'!",&%B#'=,&'!#3.,&'E#"$,&9.W/'FA0'QK!E'HIIX)Y' '! Z#'$@44'?+%44#3B#'"+@.'%..8-<"@,3)' C&

Summary of Conventional Links#! *2<@?%4'$@&#4#..'4@39.'%&#'.2--#"&@?)'>%?+'3,5#'&83.' @".',$3'&%5@,)'[Z@P@/'M48#",,"+/'#"?)\' "'#"C#2*$#"+#'.%-#'-*3%.#)2%4#*$#*#7.5%6/#3/?%)/D# N93/8L<7O& E9.FG./2H& >H/7(.8<=.9& I)-G;30)/& JK&?373& P.2.<Q.O& K?M&?.L)-G;30)/& E9.FG./2H& >H/7(.8<=.9&! Z+%"'L#3#]".'@3'"#&-.',='<,$#&'%35'?@&?8@"'?,-<4#O@"2'%&#'B%@3#5'L2'L&#%9@3B'"+@.'.2--#"&2^' D&

MBS Uplink versus Conventional Radios# Frequency Data Rate Peak Transmit Modulation Technology (MHz) (Mbit/s) Power (dbm) Scheme 802.11b 2400 11 20 PSK-CCK 802.11a/802.11g 5200/2400 54 23 OFDM Bluetooth 2400 0.723 0 FSK THIS WORK 915 96 QAM (MBS)! Q3'"+@.'$,&9/'$#'@-<4#-#3"'NF0',D#&'%'C_P' L%?9.?%""#&'4@39'",'%?+@#D#'%'5%"%'"&%3.=#&'&%"#',='`X' 0L@"a.)'! ;%"%'&%"#.'%&#'?,-<%&%L4#'",'#O@."@3B'$@&#4#..'<&,",?,4./' L8"',<#&%"#'$@"+'%'.@B3@]?%3"'&#58?"@,3'@3'<,$#&'?,.")'! *+@.'-%9#.'+@B+TL%35$@5"+'$@&#4#..'5%"%'"&%3.=#&' <,..@L4#'=,&'<,$#&'?,3."&%@3#5'5#D@?#.)' SN35;.&E9)L&TU&M(./V&.7&3;UV&WX<MIY>&-.Q<2.8&3/-&PE&</7.Z937.-&2<92G<78V[&& </&!"#$#%&'()*+,&-,./,+"),0*#1&2+3(,!"4*"((1*"4V&\)(/&'<;.H&]&>)/8V&,/2UV&%$$CU^& R&

Prior work in QAM Backscatter#!!@-84%"@,3.',='bTK!c'a'bTNF0',D#&'L%?9.?%""#&'4@39' %4,3B'$@"+'<&#4@-@3%&2'&#.84".'$#&#'.+,$3'%"'Q>>>' 1PQ;'HIJI)' _&

Scattered Fields from an Antenna#! *+#'.?%""#&@3B'=&,-'%'4,%5#5'%3"#33%'@.'$#44T93,$3' Ud&##3'J`Xe/'_%3.#3'J`f`Y' E scat (Z L )=E scat (Z a)+γ (Z L ) E anti m I ant `&

Scattered Fields from an Antenna#! *+#'.?%""#&@3B'=&,-'%'4,%5#5'%3"#33%'@.'$#44T93,$3' Ud&##3'J`Xe/'_%3.#3'J`f`Y' E scat (Z L )=E scat (Z a)+γ (Z L ) E anti m I ant! 4%56+%65,)02*"#01+,%%#5!$(0@.'5#<#35#3"',3'%3"#33%' B#,-#"&2/'."&8?"8&#/'%35'<,.#)' #$&

Scattered Fields from an Antenna#! *+#'.?%""#&@3B'=&,-'%'4,%5#5'%3"#33%'@.'$#44T93,$3' Ud&##3'J`Xe/'_%3.#3'J`f`Y' E scat (Z L )=E scat (Z a)+γ (Z L ) E anti m I ant! 4%56+%65,)02*"#01+,%%#5!$(0@.'5#<#35#3"',3'%3"#33%' B#,-#"&2/'."&8?"8&#/'%35'<,.#)'! 7$%#$$,02*"#01+,%%#5!$(0@.'5#<#35#3"',3'"+#'?,3R8B%"#' &#g#?"@,3'?,#h?@#3")' ##&

Scattered Fields from an Antenna#! *+#'.?%""#&@3B'=&,-'%'4,%5#5'%3"#33%'@.'$#44T93,$3' Ud&##3'J`Xe/'_%3.#3'J`f`Y' E scat (Z L )=E scat (Z a)+γ (Z L ) E anti m I ant! 4%56+%65,)02*"#01+,%%#5!$(0@.'5#<#35#3"',3'%3"#33%' B#,-#"&2/'."&8?"8&#/'%35'<,.#)'! 7$%#$$,02*"#01+,%%#5!$(0@.'5#<#35#3"',3'"+#'?,3R8B%"#' &#g#?"@,3'?,#h?@#3")' Γ (Z L )= Z a Z L Z a + Z L! M%?9.?%""#&@3B'$,&9.'L2'<&#.#3"@3B'%'"@-#TD%&2@3B'4,%5' @-<#5%3?#'",'"+#'%3"#33%'?%8.@3B'?+%3B#.'@3'"+#'.?%""#&#5' ]#45.'58#'",'%3"#33%T-,5#'.?%""#&@3B)' #%&

Baseband Signal Model#! *+&##'.@B3%4.'%&#' &#?#@D#5'L2'"+#'&#%5#&i' F) >3D@&,3-#3"%4' A48""#&' dg3-937g9.&bdc&,/aj(38.&b,c& #@&

Baseband Signal Model#! *+&##'.@B3%4.'%&#' &#?#@D#5'L2'"+#'&#%5#&i' F) >3D@&,3-#3"%4' A48""#&' M) F3"#33%'!"&8?"8&%4'!?%""#&@3B' dg3-937g9.&bdc&,/aj(38.&b,c& #!&

Baseband Signal Model#! *+&##'.@B3%4.'%&#' &#?#@D#5'L2'"+#'&#%5#&i' F) >3D@&,3-#3"%4' A48""#&' M) F3"#33%'!"&8?"8&%4'!?%""#&@3B' A) F3"#33%'0,5#'!?%""#&@3B' dg3-937g9.&bdc&,/aj(38.&b,c& #C&

Baseband Signal Model#! *+&##'.@B3%4.'%&#' &#?#@D#5'L2'"+#'&#%5#&i' F) >3D@&,3-#3"%4' A48""#&' M) F3"#33%'!"&8?"8&%4'!?%""#&@3B' A) F3"#33%'0,5#'!?%""#&@3B' dg3-937g9.&bdc&,/aj(38.&b,c&! A+%3B#.'@3'-84"@<%"+'"&%3.4%"#'&#?#@D#5']#45.'=&,-'"+#' %3"#33%)'! A+%3B#.'@3'<%"+'4#3B"+'[.#<%&%"@,3'5@."%3?#\'&,"%"#'%35'.?%4#'&#?#@D#5']#45.'=&,-'"+#'%3"#33%)' #D&

16-QAM Modulator Design# J) *+#'5#.@&#5'NF0'?,3."#44%"@,3' @.'5&%$3'@3'"+#'QaN'<4%3#)' H) QaN'<,@3".'%&#'?,3D#&"#5'",' &#g#?"@,3'?,#h?@#3".)' e) P&,-'&#g#?"@,3'?,#h?@#3"./' @-<#5%3?#.'%&#'?%4?84%"#5)' Ideal Quadrature 3 1 1 3?.8<9.-&M)/87.;;30)/& 3 1 1 3 In Phase Γ = [x + jy] max [x + jy]?.8<z/.-&39)g/-&3& C$&Y(LV&`#C&IA=& 3/7.//3U& Z Li Z a = Z a Z a Γ i 1+Γ i ances values may fall in #R&

Circuit Implementation#! F'JXTJ'-8O'@.'@-<4#-#3"#5'8.@3B'?%.?%5#5'F3%4,B' ;#D@?#.'F;d`Ib'!Kb"'1P'.$@"?+#.)' (c)! 08O'@.'?,3"&,44#5'L2'b'5@B@"%4'4@3#.'[&#<&#.#3"@3B'L@".'@3' %'.2-L,4\'! >%?+'@-<#5%3?#'&#<&#.#3".'%3'@35@D@58%4'.2-L,4)' #_&

Measured Impedances#,-.3;&3/-&I.38G9.-&hi&j3;G.8& Ideal Γ Measured Γ Z 1-0.15-0.19 + j0.03 Z 2-0.45-0.48 + j0.03 Z 3-0.15 + j0.3-0.16 + j0.3 Z 4-0.45 + j0.3-0.46 + j0.29 Z 5 0.45 0.44 + j0.04 Z 6 0.15 0.15 + j0.02 Z 7 0.45 + j0.3 0.44 + j0.33 Z 8 0.15 + j0.3 0.15 + j0.29 Z 9 0.45 + j0.6 0.42 + j0.63 Z 10 0.15 + j0.6 0.09 + j0.6 Z 11 0.45 + j0.89 0.44 + j0.9 Z 12 0.15 + j0.89 0.18 + j0.89 Z 13-0.15 + j0.6-0.19 + j0.62 Z 14-0.45 + j0.6-0.41 + j0.59 Z 15-0.15 + j0.89-0.14 + j0.9 Z 16-0.45 + j0.89-0.41 + j0.94 Simulated EVM 868 MHz 2.96% 915 MHz 0% 950 MHz 2.09% Measured EVM 915 MHz 3.62% Ideal Measured! C.@3B'%'jEF/'@-<#5%3?#.'$#&#'-#%.8&#5)'0#%.8&#5'D%48#.'.+,$'B,,5'%B&##-#3"'$@"+'<&#5@?"#5/'@5#%4'4,?%"@,3.'=,&'e3&f& C$&g&6$)'! E#O"/'$#'<#&=,&-#5'%'.#&@#.',=',D#&T"+#T%@&'"#.".'",'?,3]&-' "+%"'"+#'.?%""#&#5']#45.'+%D#'"+#'?,&&#?"'-%B3@"85#'%35' <+%.#)' #`&

Over-the-air Constellations# 4-PAM 4-QAM/4-PSK 16-QAM 3 bi37;35c& 3 1 Quadrature 1 1 Quadrature 0 Quadrature 1 1 1 3 3 3 1 1 3 In Phase 1 0 1 In Phase (a) (b) (c) 3 1 1 3 In Phase N3Z&<8&k;32.-&%URC&L&3B3H&49)L&3&g%@&-XLV&`#C&IA=&PE&8)G92.U&N(.&73Z&<8&793/8L<l/Z&C$$V$$$& 8HL5);8"8.2&4)9&!aJKI&3/-&C$$V$$$&8HL5);8"8.2&4)9&!V#DadKI&b#&I5k8V&%&I5k8&9.8k.20Q.;Hc& %$&

EVM and Power Consumed versus Symbol Frequency# I)-G;37)9&J)B.9&2)/8GLk0)/& </29.38.8&;</.39;H&B<7(&-373&937.U&,/29.38</Z&-373&937.&9.-G2.8&8HL5);&./.9ZH&23G8</Z&3&;39Z.9&mjI&! Z+#3'"&%3.-@""@3B'%"'`X'0L@"a.'-,584%",&'<,$#&'?,3.8-<"@,3'@.'J)b`'-Z'[JG)G'<(aL@"\'$@"+'%3'>&&,&'j#?",&' 0%B3@"85#',='`)ef'k)'! [K,$#&'-#%.8&#-#3"'5,#.'3,"'@3?485#'5%"%'B#3#&%"@,3'?@&?8@"&2)\' %#&

OTA 96 Mbit/sec Constellation#! 0#%.8&#-#3"'.#"8<i'! J)Hb'-'.#<%&%"@,3'5@."%3?#'! `JG'0_l'?%&&@#&'! f'5m@'4@3#%&'<%"?+'*o/'1?'! mhe'5m-',8"<8"'<,$#&'! f'5m@'"%b'%3"#33%'! 1#.84".i'! J`X/neX'L@".'' [bf/jfb'.2-l,4.\'! M>1'6'G)If'O'JI X '! >j0'o'`)efk'! J)b`'-Z'[JG)G'<(aL@"\' %%&

Link Budget# TABLE II 16-QAM BACKSCATTER LINK BUDGET λ P t G t, G r RCS, min. P r r max. 96 Mbps 33 cm +28 dbm 8 dbi 0.03 m 2-63.2 dbm 17.01 m 60 Mbps 33 cm +28 dbm 8 dbi 0.03 m 2-65.2 dbm 19.20 m 40 Mbps 33 cm +28 dbm 8 dbi 0.03 m 2-67.0 dbm 21.25 m! F'-%O@-8-',<#&%"@,3%4'5@."%3?#',='Jn)IJ'-'@.' <&#5@?"#5'=,&'%'`X'0L@"a.'5%"%'&%"#' F..8-<"@,3.i'! 1#%5#&'!#3.@"@D@"2'4@-@"#5'[&#"8&3'4@39'4@-@"#5\'! J'L<.a_l'.<#?"&%4'#h?@#3?2'! 0#%.8&#5'&#?#@D#&'3,@.#']B8&#',='J`'5M'! JH'5M'>LaE,'-%&B@3'[=,&'M>1',='JI Te \'! ;@p#&#3"@%4'1a!'5#"#&-@3#5'l2'-@3@-8-'5@."%3?#' L#"$##3'%32'H'<,@3".'@3'"+#'?,3."#44%"@,3)' %@&

Conclusions#! F'.#-@T<%..@D#'JXNF0' L%?9.?%""#&'-,584%",&' $%.'5#.@B3#5'%35'L8@4")'! *+#'"%B'"&%3.-@".'%'?,3"@38,8.'."&#%-',='L@".' %"'`X'0L@"a.#?'$@"+'%' -,584%",&';A'<,$#&'?,3.8-<"@,3',='J)b`'-Z' [JG)G'<(aL@"\'! NF0'L%?9.?%""#&'<,$#&'?,3.8-<"@,3'@.'GIO'4,$#&' "+%3'%36/'Z@P@'?+@<.#")' 86%65#0.*590 J)!@3B4#T?+@<'A0q!' @-<4#-#3"%"@,3' H) F5%<"@D#'>r8%4T @l%"@,3',3'"+#'1#%5#&' %!&

CMOS Micrograph# #DadKI&I)-G;37)9&,Lk;.L./7.-&</&MIY>& %C&

Thank you!! %D&