Behzad Razavi, RF Microelectronics, Prentice Hall PTR, 1998

Transcription

1 2008/Sep/17 1

2 Text Book: Behzad Razavi, RF Microelectronics, Prentice Hall PTR, 1998 References: (MSR) Thomas H. Lee, The Design of CMOS Radio-Frequency Integrated Circuits, 2/e, Cambridge University Press, Contents: (Oscillators) (PA) 3. IC (LNA) (Mixer) 2

3 Homework: % A4 80% : 35% : 35% : 20% ycchiang1970@nchu.edu.tw : : : (Lab. 717) 3

4 Introduction What is Radio Frequency? Frequency (Hz) Long wave radio AM broadcast radio Shortwave radio VHF TV FM broadcast radio Microwaves Far Infrared Infrared Visible light Traditional definition: Wavelength (m) Frequency range for radio and television transmission (1MHz 1GHz) 4

5 Band Name & Abbr. Frequency & λ Introduction Example Uses Very Low Frequency Low Frequency Medium Frequency High Frequency Very High Frequency Ultra High Frequency Super High Frequency Extremely High Frequency 3 30 khz 0 km km khz km 1 km khz 1 km 0 m 3 30 MHz 0 m m MHz m 1 m MHz 1 m 0 mm 3 30 GHz 0 mm mm GHz mm 1 mm Submarine communication, avalanche beacons, wireless heart rate monitors Navigation, time signals, AM longwave broadcasting AM (Medium-wave) broadcasts Shortwave broadcasts and amateur radio FM and television broadcasts television broadcasts, mobile phones, wireless LAN, ground-to-air and air-to-air communications microwave devices, mobile phones (W-CDMA), WLAN, most modern Radars Radio astronomy, high-speed microwave radio relay 5

6 6 Introduction Standard Prefixes da deka h hecto k kilo M mega G giga T tera Factor Abbreviation Prefix a atto f femto p pico n nano micro m milli c centi d deci Factor Abbreviation Prefix µ

7 Introduction IC high integration trend: (Circuit Area) Die Cost = (Process (Wafer Area) Cost) E.g. A device area = 30 µ m 30 µ m 8 - inch wafer area 0.1m 0.1m π Process cost = Device cost One rule for IC design NT$ NT$ Cost of on - chip devices << Cost of # of on - chip devices Cost of customers and Use fewest off-chip devices as you can # of off off - chip - chip devices devices 7

8 IC production schedule Introduction Design phase: 2 months Layout phase: 0.5~1 month Process phase: 0.5~2 months Shipping & package phase: 0.2~0.5 month Measurement: 1 months Total duration: 4.2~6.5 months Since the IC production cycle time is very long and the time to market is very tight, the design iteration should be minimized. One iteration for digital ICs, 1~2 iteration for analog/rf ICs. 8

9 Introduction How to minimize design iteration? For Foundry Offer accurate device models Active devices: corner models, Monte Carlo models Passive devices: variation ranges For Designer Current-biased scheme for analog/rf ICs Simulate circuits with most conditions (worst-case simulation) Add design margin to overcome process variations Better circuit architectures to overcome process variations 9

10 Introduction RF designer Maxwell s Equations AC / Field analysis / time domain dbm / s-parameters / dbc Smith Chart Noise Figure in db Thermal / Flicker / Shot Noise GaAs / BiCMOS / CMOS 20-transistors ICs (for one block) Network & Spectrum analyzer Cadence SpectreRF Mentor EldoRF Agilent ADS / RFDE L Digital/Analog designer Ohm s law DC / AC Volts SPICE Noise in nv/sqrt(hz) Thermal Noise CMOS 20-transistor bias circuits Oscilloscope espice hspice L

11 Introduction Figure 1.1 (a) FM transmitter, (b) FM receiver Figure 1.2 RF section of a cellphone [1] 11

12 Design Bottleneck RF and baseband processing in a transceiver RF Section Baseband Section Although the baseband section is more complex than RF section in terms of the number of devices, the RF section is still the design bottleneck of the entire system for 3 reasons: 1. Multidisciplinary Field 2. RF Design Hexagon 3. Design Tools 12

13 Multidisciplinary Field Design Bottleneck Microwave Theory Communication Theory Random Signals Signal Propagation RF Design Transceiver Architectures Multiple Access Wireless Standards CAD Tools IC Design 13

14 RF Design Hexagon Design Bottleneck Noise Power Linearity Frequency Supply Voltage Gain Design Tools Nonlinearity, time variance, and noise in RF circuits make the SPICElike tools (linear ac analysis) no longer suitable or efficient. External components cannot be modeled by typical devices in SPICE. They can usually be characterized only by S-parameters. 14

15 Applications 15

16 Applications 16

17 Applications 17

18 Applications 18

19 Analog and Digital Systems Voice Modulator Power Amplifier Carrier (a) Audio Amplifier Downconverter Demodulator Low-Noise Amplifier Carrier (b) Figure 1.6 Block diagram of a generic analog RF system: (a) transmitter, (b) receiver. 19

20 Analog and Digital Systems Digital Power Amplifier Voice ADC Voice Compression Coding Interleaving Pulse Shaping Modulator (a) Carrier Down Converter ADC Demodulator Equalizer Carrier Digital De-interleaving Decoding Audio Amplifier DAC Voice Decompression (b) Figure 1.7 Block diagram of a generic digital RF system: (a) transmitter, (b) receiver. 20

21 Analog and Digital Systems In the simplest case: the main consideration is the distance Power delivered and sensitivity of the receiver In a realistic environment: interference, multi-path, movement, etc. Signal processing will achieve a higher performance Which parts are RF electronics?

22 GaAs Choice of Technology Higher (breakdown voltage) x (higher cutoff frequency) product, semiinsulating substrate, and high-quality inductors and capacitor. Low-yield, low integration, high-cost PA s, front-end switches BiCMOS/ SiGe BiCMOS Moderate performance and integration, moderate cost CMOS High integration, low-cost Substrate coupling / loss, modeling, etc Silicon BJT SiGe HBT 22