development of a direct conversion multiband/multimode transmitter for wireless applications morgan...
TRANSCRIPT
Development of a Direct Conversion Multiband/Multimode Transmitter for Wireless
Applications
Morgan Chen
Summer Undergraduate Research Experience (SURE) 20021
Department of Electrical Engineering and Computer Science
University of California, Berkeley
Berkeley, CA 94720
1Department of Electrical and Computer Engineering
Clemson University
Clemson, SC 29634
CLEMSONU N I V E R S I T
Y
• Motivation/Objectives
• Development and Design
• Fabrication of Transmitter
• Experimental Results
• Conclusion
Outline
CLEMSONU N I V E R S I T
Y
Motivation/Objectives
• Direct Conversion, or homodyne, has fewer components
• Fewer Components = Cheaper
• Multiband transmitters allow accessing multiple frequencies
• Ultimate goal of single chip design
Table of SpecificationsParameter Specified ValueBaseband frequencies 10-30 kHzBaseband input power <-3 dBmRF frequencies 1.9 GHz and 5.8 GHzRF power output 30 dBm for 1.9 GHz and 25 dBm for 5.8 GHz
CLEMSONU N I V E R S I T
Y
Block Diagram
LO = 1.9 GHz/5.8 GHz
Baseband Signal =10 - 30 kHz
BPF1: Assume3 dB
19.7 dBm (Max for the PAbefore the 1dB gain
compression pt. for 1.9 GHz)
SKY-7G
BPF2: Assume3 dB
MGA-83563
Switchingnetwork:
Assume 3 dBloss
PA3
MGA-83563
MGA-83563MGA-83563
15 dBm (Max for thePA before the 1dB
gain compression pt.for the 5.8 GHz)
PA4
PA3 PA3
CLEMSONU N I V E R S I T
Y
Design in CircuitCAM
Example layout of 5.8 GHz patch antenna
Example layout of switch
CLEMSONU N I V E R S I T
Y
Experimental Results
Spectral plot of the SKY-7G mixer with IF = 100 KHz, LO = 1.9 GHz
CLEMSONU N I V E R S I T
Y
0.2 0.4 0.6 0.8 1 1.5 2 3 4 5 10 20 50
0.2
0.4
0.6
0.8 1
1.5
2
3
4
5
10
2050
-0.2
-0.4
-0.6
-0.8 -1
-1.5
-2
-3
-4
-5
-10
-20-50
3.8 GHz
7.8 GHz
S22HP 8719
07-15-2002 11:55:55
Smith Diagram for 5.8 GHz Patch Antenna
CLEMSONU N I V E R S I T
Y
-15
-10
-5
0
4.0 4.5 5.0 5.5 6.0 6.5 7.0 7.5
S22 MagnitudeHP 8719
07-15-2002 11:55:55
[dB
]
[GHz]
Standing Wave Ratio (SWR) Plot
CLEMSONU N I V E R S I T
Y
Conclusions
• Direct conversion multiband/multimode transmitter technology is promising
• Design may require state of the art power amplifiers
• Switch is inefficient
• Switch also suffers from parasitics
• Future research means developing the PA and switch
• Future research also requires spectral masking
CLEMSONU N I V E R S I T
Y
Acknowledgements
•National Science Foundation
•Minicircuits’s Gerry Edson
•Agilent Technologies’ Creg Ballou
•NEC's California Eastern Laboratories' David Melton and Pam Cowan
•SURE advisor Dr. A. Pham
•Graduate students S. Thumaty, D. Newlin, C. Tompkins, X. Wang, S. Manohar, J. Rudbeck, M. Lockhard, R. Hanks, S. Chopra, and A. Keerti
•And last, but not least, Dr. D. Noneaker, Director of the SURE program at Clemson University
CLEMSONU N I V E R S I T
Y
Additional Slides
• Power Budget
• Transistor diagram of the switching network
• ADS
• Baseband Harmonic Problem
CLEMSONU N I V E R S I T
Y
Part Number Power out (dBm) Gain (dB) IP3 (dBm)Input Baseband at 1.9 GHz -3Input Baseband at 5.8 GHz -3Mixer = SKY-7G at 1.9 GHz -13 -10 10Mixer = SKY-7G at 5.8 GHz -13 -10 10Switching network for 1.9 GHz -16 -3Switching network for 5.8 GHz -16 -3BPF1 = Make ourselves -19 -3BPF2 = Make ourselves -19 -3PA1 = MGA-83563 0.35 19.35 29PA2 = MGA-83563 19.7 19.35 29PA3 = MGA-83563 -2 17 29PA4 = MGA-83563 15 17 29
Antenna: 1.9 GHz: Aceteq
Power Budget
CLEMSONU N I V E R S I T
Y
Transistor diagram of the switching network
VCC
VCC
Inverter
Delay
Pass GatesControl Line
Data Line
Line Out 1
Line Out 2
(CL=1)
(CL = 0)
SPDT
CLEMSONU N I V E R S I T
Y
Design in Advanced Design System
ADS Linecalc Tool
Transmitter Block Diagram
CLEMSONU N I V E R S I T
Y
Baseband Harmonic Images Problem
Wbaseband
abaseband
Wlo
alo
w
w
w
0.5*abaseband*alo
Wlo+WbasebandWlo-Wbaseband
Wlo
Small baseband frequencies = Spurious signals close to transmit signal!