f o r a z e r o
`t r a n s c e i v e r
`i n t e g r a t e d S i b i p o l a r RF
`An
`m o b i l e r a d i o f r o n t e n d of a hand p o r t a b l e phone.
`
`I F 900 MHz GSM d i g i t a l
`
`Jan Sevenhans (1). Arnoul Vanwelsenaers (21, J. Wenin (11, J. Baro (2)
`
`(1) A l c a t e l B e l l Telephone, Antwerp, Belgium
`(2) A l c a t e l Radio Telephone, Colombes, France
`
`A b s t r a c t
`
`A s i n g l e c h i p s o l u t i o n f o r a GSM 900 MHz RF TX
`q u a d r a t u r e modulator
`and
`quadrature
`RX
`demodulator was designed and
`f a b r i c a t e d
`i n a
`9 gHz S i l i c o n b i p o l a r technology.
`The t r a n s m i t modulator i s a d i r e c t upconverter
`and t h e r e c e i v e demodulator operates
`i n a z e r o
`I F a r c h i t e c t u r e .
`T h i s d e v i c e i s one o f t h e key-components o f a
`pocket
`s i z e
`handportabl e
`phoneset
`f o r
`a p p l i c a t i o n i n t h e GSM pan European d i g i t a l
`m o b i l e r a d i o system.
`The consumption f r o m t h e
`i s 25 mA i n RX mode and 45 mA
`b a t t e r y
`i n
`TX mode.
`r e g u l a t e d
`The c i r c u i t i s powered
`from a 5 V
`s u p p l y v o l t a g e .
`
`1.
`
`INTRODUCTION
`
`The success o f GSM handportable phone s e t s
`depends meanly on
`t h e l e v e l o f i n t e g r a t i o n
`of
`t h e system f u n c t i o n a l b u i l d i n g b l o c k s i n
`t h e minimum number o f VLSI c i r c u i t s .
`r e s e a r c h l a b s a r e pub1 i s h i n g
`Today s e v e r a l
`work on GSM phone s e t s c o n s i s t i n g o f a
`number of VLSI's.
`U s u a l l y one has a CMOS
`d i e
`f o r
`t h e v o i c e
`t r a n s c e i v e r
`and
`t h e
`speech codec,
`two o r 3 CMOS devices f o r t h e
`GSM
`system c o n t r o l ,
`t h e decoding o f
`t h e
`d i g i t a l v o i c e d a t a
`from
`t h e quadrature I
`and Q v e c t o r phase diagram and another CMOS
`d i e t o do t h e AID and D/A and t h e channel
`t h e GMSK shaped i n phase I and
`f i l t e r i n g of
`t h e q u a d r a t u r e Q phase v e c t o r s . On
`t o p o f
`t h a t ,
`t o d a y
`f o r
`t h e RF-front-end
`t h e
`a v a i l a b l e components use separate s i l i c o n
`f o r t h e RF r e c e i v e r and t r a n s m i t t e r .
`
`i s growing
`system development
`The GSM
`t h e
`f e a s i b i l i t y o f a pocket s i z e
`towards
`h a n d p o r t a b l e phone by e x p l o i t i n g t h e s t a t e
`o f t h e a r t sub m i c r o n CMOS
`t e c h n o l o g i e s f o r
`t h e d i g i t a l GSM
`system c i r c u i t r y and
`t h e
`baseband I and Q analog f i l t e r s and A-DID-A
`conversion.
`
`i n t e g r a t i o n
`f u r t h e r
`The
`t h e CMOS
`o f
`baseband and d i g i t a l
`c i r c u i t r y
`i s o n l y
`l i m i t e d b y t h e minimum dimensions of CMOS
`techno1 ogy.
`On t h e o t h e r hand t h e r e i s t h e RF-front end
`
`I n a pocket s i z e
`o p e r a t i n g a t 900 MHz.
`h a n d p o r t a b l e phone we cannot a f f o r d t o have
`another
`t w i n
`c h i p
`s e t
`f o r
`t h e
`RF
`t r a n s m i t t e r and t h e RF r e c e i v e r .
`
`I n t h i s paper we d e s c r i b e
`t h e s i n g l e c h i p
`s o l u t i o n
`f o r o u r z e r o
`I F approach
`t o
`t h e
`GSM RF-transceiver.
`25 mA
`The
`d e v i c e
`consumes
`r e c e i v e
`i n
`maximum g a i n mode and 45 mA i n t r a n s m i t
`t o
`o b t a i n a r e c e i v e maximum conversion g a i n o f
`25 dB, an I P 3 o f 0 dBm and a r e c e i v e m i x e r
`n o i s e f i g u r e o f 18 dB.
`I n t r a n s m i t mode t h e c i r c u i t d e l i v e r s 0 dbm
`on a balanced o u t p u t
`t o d r i v e
`t h e power
`a m p l i f i e r
`o f
`t h e
`pocket
`s i z e
`2
`W
`handportable phone s e t .
`
`2. SYSTEM ARCHITECTURE
`* To o b t a i n
`t h e o v e r a l l 6 dB system n o i s e
`f i g u r e we use an 18 dB g a i n
`low n o i s e
`a m p l i f i e r w i t h a 2,7 dB n o i s e f i g u r e .
`The LNA has 2 g a i n modes
`t o p r o v i d e a
`10 dB g a i n s w i t c h f o r h i g h i n p u t l e v e l s .
`* The r e c e i v e mixers p e r f o r m a d i r e c t down
`conversion o f
`t h e phase modulated GMSK
`935/960 MHz
`i n p u t
`s i g n a l
`and
`t h e
`q u a d r a t u r e demodulation of
`t h e
`i n phase
`and
`t h e
`quadrature
`base-band
`phase
`The band w i d t h o f t h e I and Q
`v e c t o r s .
`v e c t o r s
`i s
`l i m i t e d
`t o 360 kHz u s i n g a
`f i r s t o r d e r p r e b l o c k i n g f i l t e r .
`The conversion g a i n o f t h e I and Q RX
`mixers i s 6 dB.
`* F o l l o w i n g t h e m i x e r s we have a gainstage
`on
`each
`o f
`them.
`These
`p o s t m i x e r
`a m p l i f i e r s (PMA) p r o v i d e an e x t r a 19 dB
`g a i n i n t h e b i p o l a r RF-frontend b e f o r e we
`h i t
`t h e
`CMOS
`base
`band
`r e c e i v e
`f i l t e r i n g .
`I n t h e PMA we have another
`2 MHz
`p r e b l o c k i n g
`f i l t e r
`t o
`suppress
`i n t e r f e r i n g o f
`t h e wanted
`base
`band
`s i g n a l s with h i g h b l o c k i n g s i g n a l s .
`* The I and Q RX-mixers
`a r e d r i v e n by
`quadrature
`Local
`o s c i 1 l a t o r
`(LO)
`s i g n a l s .
`The quadrature Lo s i g n a l s a r e
`d e r i v e d on c h i p f r o m a balanced Lo i n p u t .
`* The
`t r a n s m i t
`s e c t i o n uses
`two a c t i v e
`m i x e r s t o compose t h e phase modulated GSM
`890/915 MHz RF
`s i g n a l .
`To o b t a i n
`t h e
`0 d8m
`d r i v e
`s i g n a l
`f o r
`t h e
`power
`
`7.7.1
`
`IEEE 1991 CUSTOM INTEGRATED CIRCUITS CONFERENCE
`
`CH2994-2/91/0000/0031 $1.00 1991 IEEE
`
`-
`
`TCL EXHIBIT 1023
`Page 1 of 4
`
`

`
`balanced o u t p u t
`t h e Tx-mixer
`a m p l i f i e r
`s i g n a l
`i s f e d
`i n t o an on-chip pre-power
`i s o p e r a t i n g i n
`a m p l i f i e r (PPA).
`The PPA
`t h e
`l i n e a r mode
`t o a v o i d
`i n t e r m o d u l a t i o n
`i n t h e t r a n s m i t s i g n a l .
`3. RX-MIXERS
`
`i s d i c t a t e d by
`The d e s i g n o f t h e RX mixers
`t h e
`requirements on n o i s e and d i s t o r t i o n
`l i m i t a t i o n s .
`
`f r o n t end
`i s demanding t h e RF
`The GSM spec
`t o
`cope w i t h
`b l o c k i n g
`s i g n a l s
`up
`t o
`-23 dBm.
`Since we have 17 dB g a i n
`i n t h e
`low n o i s e a m p l i f i e r
`(LNA) o f t h e RF
`f r o n t
`t h e RX mixers a r e d e a l i n g w i t h -6 dBm
`end,
`b l o c k i n g l e v e l s a t 3 MHz d i s t a n c e from t h e
`c a r r i e r .
`To b r i n g t h e 1 dB compression o f
`t h e
`d i f f e r e n t i a l
`i n p u t
`p a i r
`o f
`t h e
`g i l b e r t c e l
`r u n n i n g
`on
`a
`x
`1,5 mA
`2
`t a i l c u r r e n t up
`t o
`t h i s
`l e v e l , we need 2
`20 dB e m i t t e r degeneration.
`Then these 200
`ohm e m i t t e r
`r e s i s t o r s a r e
`t h e 1 i m i t a t i o n
`f o r t h e a c h i e v a b l e n o i s e f i g u r e : 18 dB.
`
`i n p u t t r a n s i s t o r s o f t h e RX-mixers have
`The
`o f 25 ohm
`i n
`t h e 9 GHz
`f T p o l y
`an RBB
`s i l i c o n e m i t t e r
`technology used
`f o r
`t h i s
`a p p l i c a t i o n .
`o f
`f i g u r e
`n o i s e
`a
`i n
`T h i s
`r e s u l t s
`t o p o f t h i s we have an e x t r a
`14.06 dB. On
`3 dB on
`t h e n o i s e performance because o f
`t h e
`image n o i s e
`i n t h e s i n g l e s i d e band
`phase modulated RF-signal.
`
`4. THE POST MIXER AMPLIFIERS
`t h e I and Q v e c t o r s can a t t a c k t h e
`Before
`CMOS channel f i l t e r i n g c i r c u i t r y we have t o
`p r o v i d e them an e x t r a g a i n o f 19 dB on t o p
`o f t h e 6 dB o f t h e m i x e r s .
`But b e f o r e we do t h i s we must c o n s i d e r t h e
`GSM b l o c k i n g l e v e l s .
`t h e y a r e
`r e c e i v e r ,
`For
`t h e handportable
`from t h e c a r r i e r on
`s p e c i f i e d a t 3 MHz away
`I t should be
`a
`-23 dbm maximum
`l e v e l .
`c l e a r t h a t we need t o f i l t e r these b l o c k i n g
`l e v e l s down by 2 15 dB b e f o r e we d e l i v e r
`them t o t h e PMA g a i n o p e r a t i n g on
`t h e 5 V
`r a i l t o r a i l power supply.
`t h e 3 MHz
`T h i s 15 dB down
`f i l t e r i n g o f
`b l o c k i n g l e v e l s i s demanding a f i r s t o r d e r
`p o l e a t 2 300 kHz.
`T h i s p o l e i s r e a l i s e d by t h e c a p a c i t o r s on
`OB,
`NOB
`and
`I B ,
`NIB,
`each
`o f
`them
`r e s p e c t i v e l y c u t t i n g t h e spectrum o f t h e I
`and Q phase v e c t o r s above 300 kHz.
`
`f i 1 t e r s a r e
`f i r s t o r d e r b l o c k i n g
`These
`c o n f i g u r r e d
`u s i n g e x t e r n a l
`c a p a c i t o r s
`t o
`a l l o w
`f o r moderate
`c o l l e c t o r
`r e s i s t o r
`values i n t h e m i x e r .
`
`5. THE OUADRATURE PHASE GENERATOR
`
`The main r e s t r i c t i o n s f o r t h e design o f t h e
`phase s h i f t e r a r e noise, phase accuracy,
`
`RX
`
`TX
`
`7.7.2
`
`g a i n matching and d r i v e c a p a b i l i t y .
`main
`l i m i t a t i o n
`i s power consumption.
`t h e
`l i t e r a t u r e
`one
`f i n d s m a i n l y
`o p t i o n s :
`
`The
`I n
`two
`
`f i r s t do a
`t h e d i q i t a l o o t i o n were you
`frequency
`d o u b l i n g
`and
`a f t e r w a r d s
`a
`d i v i s i o n b y 2
`i n a
`Johnson Counter
`t o
`o b t a i n t h e 2 quadrature Lo s i g n a l s ;
`t h e RC/CR o o t i o n u s i n g a RC-integrator and,
`a C R - d i f f e r e n t i a t o r
`as a +45"/-45
`phase
`s h i f t e r and a
`l i m i t i n g a m p l i f i e r t o f o l l o w
`r e s t o r i n g t h e 0" and 90" Lo s i g n a l l e v e l t o
`o b t a i n equal amplitude Lo d r i v e
`l e v e l on
`b o t h RX and TX I and Q mixers.
`i n h e r e n t
`t h e
`The
`d i g i t a l
`o p t i o n
`has
`advantage o f t h e c o r r e c t phase r e l a t i o n o f
`t h e q u a d r a t u r e Lo-signals
`r e s u l t i n g
`from
`t h e devide by 2.
`But
`t o o b t a i n low phase
`n o i s e
`(-148 dBc)
`t h i s approach
`i s v e r y
`power hungry.
`t h e RC/CR
`F o r
`t h i s
`reason we have used
`approach and
`t o reach
`t h e phase accuracy
`requirement o f
`t h e GSM
`s p e c i f i c a t i o n , we
`p r o v i d e a phase a d j u s t c o r r e c t i o n
`i n p u t .
`The phase c o r r e c t i o n v o l t a g e a p p l i e d h e r e
`i s d e r i v e d
`from a phase e r r o r o b s e r v a t i o n
`as
`t h e phase
`t r a j e c t o r i e s a r e converted
`i n t o RX-bi n a r y data.
`
`6. THE TX-MIXERS
`
`t h e design was d r i v e n by
`I n t h e Tx-mixers
`power
`economising
`c o n s i d e r a t i o n s m a i n l y .
`We have t o p r o v i d e a 0 dBm TX s i g n a l
`l e v e l
`power
`r e q u i r e d
`by
`t h e
`e x t e r n a l
`2 W
`a m p l i f i e r .
`Run
`t h e mixers
`a t a
`h i g h
`
`Summary o f t h e measured
`performance parameters
`I
`I I Supply c u r r e n t i n max g a i n mode
`Noise F i g u r e o f mixers + PMAs
`I I/Q
`(max g a i n mode)
`
`g a i n matching
`
`.~
`
`I / Q c o n v e r s i o n g a i n v o l t a g e
`I/Q q u a d r a t u r e phase e r r o r f o r
`OV phase a d j u s t i n p u t
`I/Q o f f s e t v o l t a g e f o r
`150 mVp d i f f e r e n t i a l Lo d r i v e
`and RX i n p u t l e v e l -
`t o -10 dBm
`
`Supply c u r r e n t
`
`I
`I C a r r i e r r e j e c t i o n
`
`Balanced o u t p u t power l e v e l
`
`Image r e j e c t i o n
`
`25 mA
`
`18 dB
`
`0,14 dB
`
`16 x
`
`1 "
`
`
`
`20 mV 2
`5 mV
`
`45 mA
`
`0 dBm
`
`40 dBs
`
`36 dBs
`
`TCL EXHIBIT 1023
`Page 2 of 4
`
`

`
`t h e 0 dBm o u t p u t
`t o o b t a i n
`l e v e l
`c u r r e n t
`l e v e l on t h e balanced m i x e r open c o l l e c t o r
`would have been a 50 % waste o f power.
`I n s t e a d o f r u n n i n g 2 mixers a t t h e r e q u i r e d
`0 dBm power
`l e v e l
`t o be more
`i t appeared
`b a t t e r y - f r i e n d l y
`t o r u n
`t h e mixers a t a
`moderate
`t a i l c u r r e n t
`( d i c t a t e d bv n o i s e
`and d i s t o r t i o n requirements) and spend
`t h e
`nominal Dower
`i n one on c h i p we-power
`.
`.
`
`a m p l i f i e r ' ,
`d r i v i n g
`a
`balanced
`open
`c o l l e c t o r
`RF TX s i g n a l
`over
`a
`b a l u n
`t r a n s f o r m e r i n t o t h e power a m p l i f i e r .
`
`7 .
`
`CONCLUSION
`
`A s i n g l e c h i p s o l u t i o n f o r a GSM 900 MHz RF
`TX q u a d r a t u r e modulator and RX quadrature
`demodulator was designed and
`f a b r i c a t e d i n
`a 9 gHz S i l i c o n b i p o l a r technology.
`d i r e c t
`The
`t r a n s m i t modulator
`i s
`a
`u p c o n v e r t e r and
`t h e
`r e c e i v e demodulator
`operates i n a z e r o I F a r c h i t e c t u r e .
`T h i s d e v i c e i s one o f t h e key-components of
`a p o c k e t s i z e handportabl e phoneset
`f o r
`a p p l i c a t i o n i n t h e GSM pan European d i g i t a l
`m o b i l e r a d i o system.
`The consumption
`from
`t h e b a t t e r y i s 25 mA
`i n RX mode and 45 mA
`i n TX mode.
`The c i r c u i t i s powered from a 5 V r e g u l a t e d
`s u p p l y v o l t a g e .
`
`8. ACKONWLEDGEMENTS
`
`t o
`thanks
`express many
`a u t h o r s
`The
`H. Rokos, P. Gaussen, P. Denny,
`R. Baldey
`and R i c k Van V l i e t
`f o r t h e i r c o n t r i b u t i o n
`t o t h e r e a l i s e d component.
`
`9. REFERENCES
`-
`
`M o n o l i t i c S i l i c o n RF c i r c u i t y .
`achievements and f u t u r e p o t e n t i a l .
`P. H. Saul
`ESSC/RC'90 p. 25-28.
`
`C u r r e n t
`
`-
`imbalances i n d i g i t a l
`Quadrature m i x e r
`TDMA M o b i l e r a d i o r e c e i v e r s .
`Z u r i c h
`A.
`B a i e r ,
`1990
`I n t e r n a t i o n a l
`Seminar
`on
`d i g i t a l
`communications,
`p 181-194.
`
`-
`
`-
`
`A 3 g b i t / s B i p o l a r Phase s h i f t e r and AGC
`Amp1 i f i e r .
`H.M. Rein e t a l . , 1989 I E E E I n t e r n a t i o n a l
`S o l i d s t a t e c i r c u i t conference.
`
`DECT f r o n t end h i g h frequency a m p l i f i e r .
`Design
`f o r
`R i s t o
`PitkSnen,
`VLSI
`mobi l e / c e l l u l a r
`Telephony,
`F i n 1 and
`18-23 June 1990.
`
`Photomicrograph o f t h e s i n g l e c h i p RF GSM 900
`MHz
`q u a d r a t u r e modulator-demodul a t o r
`(Chip
`a r e a i s 2.5 mm x 2,5 mm).
`
`7.7.3
`
`TCL EXHIBIT 1023
`Page 3 of 4
`
`

`
`>
`
`cv
`> 8-
`
`do01 tl3MOd
`
`O X l N -
`
`O X 1
`I ON3
`
`I
`
`7.7.4
`
`TCL EXHIBIT 1023
`Page 4 of 4