1. A Dual-Band
Direct Conversion / VLIF
Transceiver for
850GSM / GSM / DCS / PCS
Stephen Dow, Brian Ballweber, Ling-Miao Chou, David Eickbusch,
Jim Irwin, Gary Kurtzman, Praveen Manapragada, David Moeller,
Jeyanandh Paramesh, Greg Black, Robert Wollscheid, Ken Johnson
Motorola Inc.
Austin TX; Libertyville IL

2. Outline
Overview
Transceiver
SiGe:C BiCMOS Process
Block Detail
LNA, AGC
Mixer
Quadrature Dividers
Baseband
VCO, TX Buffer
Performance Summary

3. Transceiver Features
Direct Conversion or VLIF Operation
Supported Bands: 850GSM, GSM, DCS, PCS
Dual-Input
Pin Compatible Quad-Input Optional
Highly Integrated
LNAs with Adjustable Gain Control (AGC)
Quadrature Mixers and Dividers
Baseband Filters with Variable Gain/BW, Tracking,
and DC Offset Correction
Internal RX and TX VCOs
Part of Complete GSM/GPRS Platform
48-pin QFN 7x7x1mm Plastic Package

4. Transceiver Block Diagram

5. Transceiver Die Photo
LNA Mixer
VCO
SPI PMA
Baseband
TX
Buf

6. SiGe:C BiCMOS
SiGe:C HBT
fT=46GHz, fmax=84GHz
(AE 0.4x0.8um2 @ 0.5mA)
CMOS
fT=38GHz @ 2V (NMOS)
Metal
Up to 4-Layer Aluminum
10um Thick Cu (2 mOhm/sq)
Capacitor
Double Poly (4.0fF/um2)
High-Q MIM (1.6fF/um2)
Resistor
Diffused & Polysilicon
(50 to 1.5k Ohm/sq)
SEM Photos of Thick Copper

7. Low Noise Amplifier (LNA)
Differential LNA
Dual Paths
850GSM / GSM
DCS / PCS
Gain: 21dB
NF: 1.5dB
IIP3: -5dBm
P1dB: -14dBm
LO->RF: -120dBm
Integrated Coils
LNA-Mixer Transformer
Degeneration Inductors

8. LNA Performance
GSM DCS
18
18.5
19
19.5
20
20.5
21
21.5
22
925
930
935
940
945
950
955
960
1
1.25
1.5
1.75
2
2.25
2.5
2.75
3
Gain (dB)
NF (dB)
Frequency (MHz)
18
18.5
19
19.5
20
20.5
21
21.5
22
1805
1815
1825
1835
1845
1855
1865
1875
1
1.25
1.5
1.75
2
2.25
2.5
2.75
3
Gain (dB)
NF (dB)
Frequency (MHz)

9. Adjustable Gain Control (AGC)
RF Gain selectable in 1.1dB steps
Linear attenuation in dB/step
50dB of RF Gain range
Limited by Layout/Package
Attenuation Slope set with unit resistors
Variation limited by resistor matching
Immune to process/supply/temperature

10. AGC Performance
Gain @ 1850MHz vs Supply/Temperature/DAC
-10
0
10
20
30
40
50
60
70
0 10 20 30 40 50 60
AGC DAC Setting
Gain(dB)

11. Quadrature Mixer
Gilbert Cell
Quadrature Mixer
Common-Base
Input
Gain: 10dB
IIP2: 65dBm
IIP3: 14dBm
NF ssb: 14dB
P1dB: 0dBm

12. Quadrature Divider

13. 850GSM/GSM Quadrature
Temp -40C
Temp 25C
Temp 85C
Frequency (MHz)
Frequency (MHz)Frequency (MHz)
Angle(degrees)
Mag(dB)
Mag(dB)
Quadrature Phase Amplitude Mismatch
Image Rejection
89
89.5
90
90.5
91
870 890 910 930 950
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
870 890 910 930 950
-70
-65
-60
-55
-50
-45
-40
870 890 910 930 950

14. DCS/PCS Quadrature
89
89.5
90
90.5
91
1800 1850 1900 1950 2000
-0.15
-0.1
-0.05
0
0.05
0.1
0.15
1800 1850 1900 1950 2000
-60
-55
-50
-45
-40
-35
-30
1800 1850 1900 1950 2000
Temp -40C
Temp 25C
Temp 85C
Frequency (MHz)
Frequency (MHz)Frequency (MHz)
Angle(degrees)
Mag(dB)
Mag(dB)
Quadrature Phase Amplitude Mismatch
Image Rejection

15. Baseband
Baseband Filter
4-pole Filter (1-pole, 1-pole, 2-pole stages)
Tracking Oscillator Maintains Pole Over PVT
Adjustable Gain: 6.5dB to 36.5dB
DC Offset Correction (DCOC)

16. Baseband Performance
0
5
10
15
20
25
30
35
40
10 100 1000
Temp 25C Temp 85C Temp -40C
Frequency (kHz)
Gain(dB)

17. RX / TX VCO
Voltage Controlled Oscillator
Differential Cross-Coupled
MOS VVC Tuning Element
4GHz Operation
No TX to VCO Interaction
Simple I/Q LO Generation
18% Tuning Range
No Band Switch Req'd
Voltage Sourced Oscillator
Integrated Low-Noise
Voltage Regulator
VCC

18. RX VCO Performance
RX VCO Tuning: -40C, 25C, 85C
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4
4.1
4.2
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
Vtune (V)
Frequency(GHz)
Tuning Range for
850GSM/GSM/DCS/PCS
3476MHz-3980MHz

19. TX Output Buffer
Differential Output Transformer
Diff -> SE Conversion
Gains 3dB Noise Performance
Broadband - Flat Over Band
Separate 900/1800MHz Outputs
Drives 50 Ohm Load
No External Components Req'd
12dBm @ 900MHz
10dBm @ 1800MHz

20. -180
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
1.00E+04 1.00E+05 1.00E+06 1.00E+07 1.00E+08
900MHz TX Output NoiseMag(dBc/Hz)
Frequency Offset (Hz)
GSM 5.05 Spec
Measured @ 20MHz
-168 dBc/Hz
HP4352A floor

21. -180
-170
-160
-150
-140
-130
-120
-110
-100
-90
-80
-70
1.00E+04 1.00E+05 1.00E+06 1.00E+07 1.00E+08
1800MHz TX Output NoiseMag(dBc/Hz)
Frequency Offset (Hz)
HP4352A floor
Measured @ 20MHz
-164.5 dBc/Hz
GSM 5.05 Spec

22. Performance Summary
850GSM/GSM DCS/PCS
Gain 67.5dB 67.5dB
NF / Sensitivity 2.2dB / -112dBm 2.4dB / -112dBm
IIP2 +44dBm +44dBm
IIP3 -7dBm -7dBm
1dB Compression -21dBm -21dBm
Image Rejection 50dB 45dB
RX Phase Noise -141dBc/Hz @ 3MHz -138dBc/Hz @ 3MHz
Max Blocker @
3MHz, 8dB SNR
-22dBm -25dBm
TX Phase Noise -168dBc/Hz @ 20MHz -164.5dBc/Hz @ 20MHz
TX Output Power +12dBm +10dBm
LO-to-RF Leakage -120dBm -120dBm
Current RX 97mA / TX 115mA RX 91mA / TX 105mA
Standby Current
Voltage
0.3uA
2.6V to 2.9V

23. Package and Chipset
Transceiver Part of Complete GSM/GPRS Platform
48-Pin 7x7x1mm QFN (Quad Flat Non-Leaded) Package
Package has Backside Metallization for GND Connection
GND
Plate
GSM/GPRS Platform Example
(single-sided board)