Transcript Workstations & Multiprocessors

RFIC Design and Testing for Wireless
Communications
A PragaTI (TI India Technical University) Course
July 18, 21, 22, 2008
Lecture 1: Introduction
Vishwani D. Agrawal
Foster Dai
Auburn University, Dept. of ECE, Auburn, AL 36849, USA
1
Abstract
This course discusses design and testing of RF integrated circuits
(RFIC). It is suitable for engineers who plan work on RFIC but did not
have training in that area, those who work on IC design and wish to
sharpen their understanding of modern RFIC design and test methods,
and engineering managers. It is an abbreviated version of a onesemester university course. Specific topics include semiconductor
technologies for RF circuits used in a wireless communications system;
basic characteristics of RF devices – linearity, noise figure, gain; RF
front-end design – LNA, mixer; frequency synthesizer design – phase
locked loop (PLL), voltage controlled oscillator (VCO); concepts of
analog, mixed signal and RF testing and built-in self-test; distortion –
theory, measurements, test; noise – theory, measurements, test; RFIC
SOCs and their testing.
2
Objectives
 To acquire introductory knowledge about integrated circuits
(IC) used in radio frequency (RF) communications systems.
 To learn basic concept of design of RFIC.
 To learn basic concepts of RFIC testing.
3
Outline
 Introduction to VLSI devices used in RF communications
■ SOC and SIP
■ Functional components
■ Technologies
 Design concepts and selected case studies
 Test concepts
■ Basic RF measurements
■ Distortion characteristics
■ Noise
■ SOC testing and built-in self-test (BIST)
4
References
1.
M. L. Bushnell and V. D. Agrawal, Essentials of Electronic Testing for Digital,
Memory & Mixed-Signal VLSI Circuits, Boston: Springer, 2000.
2.
J. Kelly and M. Engelhardt, Advanced Production Testing of RF, SoC, and
SiP Devices, Boston: Artech House, 2007.
3.
B. Razavi, RF Microelectronics, Upper Saddle River, New Jersey: Prentice
Hall PTR, 1998.
4.
J. Rogers, C. Plett and F. Dai, Integrated Circuit Design for High-Speed
Frequency Synthesis, Boston: Artech House, 2006.
5.
K. B. Schaub and J. Kelly, Production Testing of RF and System-on-a-Chip
Devices for Wireless Communications, Boston: Artech House, 2004.
5
Schedule, July 18, 2008
09:00AM – 10:30AM
Lecture 1
10:30AM – 11:00AM
Break
11:00AM – 12:30PM
Lecture 2
12:30PM – 01:30PM
Lunch
01:30PM – 03:00PM
Lecture 3
03:00PM – 03:30PM
Break
03:30PM – 05:00PM
Lecture 4
Introduction
Agrawal
Power & Gain Agrawal
Distortion
Agrawal
Noise
Agrawal
6
Schedule, July 21, 2008
09:00AM – 10:30AM
Lecture 5
10:30AM – 11:00AM
Break
11:00AM – 12:30PM
Lecture 6
12:30PM – 01:30PM
Lunch
01:30PM – 03:00PM
Lecture 7
03:00PM – 03:30PM
Break
03:30PM – 05:00PM
Lecture 8
RF Design I
Dai
RF Design II
Dai
RF Design III Dai
RF Design IV Dai
7
Schedule, July 22, 2008
09:00AM – 10:30AM
Lecture 9
10:30AM – 11:00AM
Break
11:00AM – 12:30PM
Lecture 10
12:30PM – 01:30PM
Lunch
01:30PM – 03:00PM
Lecture 11
03:00PM – 03:30PM
Break
03:30PM – 05:00PM
Lecture 12
RF Design V
Dai
RF Design VI Dai
ATE & SOC Test Agrawal
BIST
Dai
8
An RF Communications System
Superheterodyne Transceiver
0°
VGA
LNA
Phase
Splitter
LO
Duplexer
90°
ADC
LO
DAC
0°
PA
VGA
Phase
Splitter
LO
90°
Digital Signal Processor (DSP)
ADC
DAC
RF
IF
BASEBAND
9
An Alternative RF Communications System
Zero-IF (ZIF) Transceiver
0°
LNA
Phase
Splitter
LO
Duplexer
90°
ADC
DAC
0°
Phase
Splitter
PA
LO
90°
Digital Signal Processor (DSP)
ADC
DAC
RF
BASEBAND
10
Components of an RF System
Radio frequency
● Duplexer
● LNA: Low noise amplifier
● PA: Power amplifier
● RF mixer
● Local oscillator
● Filter
Intermediate frequency
Mixed-signal
● ADC: Analog to digital
converter
● DAC: Digital to analog
converter
Digital
● Digital signal processor
(DSP)
● VGA: Variable gain amplifier
● Modulator
● Demodulator
● Filter
11
Duplexer
TDD: Time-Division
Duplexing
FDD: FrequencyDivision Duplexing
● Same Tx and Rx frequency
● RF switch (PIN or GaAs FET)
● Less than 1dB loss
Rx
● Tx to Rx coupling (-50dB)
● More loss (3dB) than TDD
● Adjacent channel leakage
fr
ft
Rx
fr
Tx
TDD command
Tx
ft
12
LNA: Low Noise Amplifier
 Amplifies received RF signal
 Typical characteristics:
● Noise figure
● IP3
● Gain
● Input and output impedance
● Reverse isolation
● Stability factor
2dB
– 10dBm
15dB
50Ω
20dB
>1
 Technologies:
● Bipolar
● CMOS
 Reference: Razavi, Chapter 6.
13
PA: Power Amplifier
 Feeds RF signal to antenna for transmission
 Typical characteristics:
● Output power
● Efficiency
● IMD
● Supply voltage
● Gain
● Output harmonics
● Power control
● Stability factor
+20 to +30 dBm
30% to 60%
– 30dBc
3.8 to 5.8 V
20 to 30 dB
– 50 to – 70 dBc
On-off or 1-dB steps
>1
 Technologies:
● GaAs
● SiGe
 Reference: Razavi, Chapter 9.
14
Mixer or Frequency (Up/Down) Converter
 Translates frequency by subtracting local oscillator (LO)
frequency
 Typical characteristics:
● Noise figure
● IP3
● Gain
● Input impedance
● Port to port isolation
12dB
+5dBm
10dB
50Ω
10-20dB
 Tecnologies:
● Bipolar
● MOS
 Reference: Razavi, Chapter 6.
15
Passive Mixer
nFET
V(RF)
V(IF)
RL
V(LO)
16
Active Mixer
VDD
V(IF)
V(LO)
V(RF)
17
LO: Local Oscillators
 Provide signal to mixer for down conversion or upconversion.
 Implementations:
● Tuned feedback amplifier
● Ring oscillator
● Phase-locked loop (PLL)
● Direct digital synthesizer (DDS)
18
Phase Splitter
 Splits input signal into two same frequency outputs that differ
in phase by 90 degrees.
 Used for image rejection.
C
R
Vout_1
Vin
Vout_2
R
C
19
SOC: System-on-a-Chip
 All components of a system are implemented on the same VLSI
chip.
 Requires same technology (usually CMOS) used for all
components.
 Components not implemented on present-day SOC:
● Antenna
● Power amplifier (PA)
20
SIP: System-in- Package
 Several chips or SOC are included in a package.
 Routing within SIP may be provided via a semiconductor
substrate.
 RF communications system may contain:
■ SIP, containing
● SOC consisting of
 CMOS digital and mixed-signal components (DSP, ADC, DAC)
 CMOS LNA and mixers
 CMOS DDS
 Filters
■ Power amplifier (PA)
■ Antenna
21
Dimensions of RF Design
Communication theory
Microwave theory
Random signals
Signal propagation
RF
Design
Wireless standards
Transceiver architecture
IC design
CAD tools
22
RF Design Hexagon
Noise
Power
Frequency
Linearity
Supply voltage
Gain
23
Technologies
 GaAs:
■ High frequency
■ High power
■ Used in PA and front-end switches
■ Low yield, expensive to manufacture
■ Not integrated on silicon chips
 Silicon bipolar and BiCMOS
 Silicon CMOS, suitable for tens of GHz
 SiGe
■ Possible replacement for GaAs
■ Can be integrated on silicon chips
24
Problem to Solve
 Analyze the function of phase splitting for image rejection in
the following circuit:
LPF
90o
sin ωLOt
RF
+
cos ωLOt
IF
LPF
25