E3 237 Integrated Circuits for Wireless Communication

Gaurab BanerjeeDepartment of Electrical Communication Engineering,

Indian Institute of Science, Bangalorebanerjee@ece.iisc.ernet.in

Lecture 1: Introduction

Course Web Page:

https://ece.iisc.ac.in/~banerjee/course_E3237/index.htm

Class Timings:

Tuesdays/Thursdays, 1100-1230 IST, Room 1.08 , ECE Bldg.Please be on Time!

Office hours:

By appointment

Class Mailing List:

Please send me an email with “E3-237 mailing list” in the subject line.

Administrative Matters

Grading and Course Structure:

The grading will be based on a project and the related research milestones quantified by:

1) 10% ==> Review 1 ==> Basic idea & specs 2) 20% Paper Presentation

(This should be from a major journal, published in the last 2 years)3) 20 % ==> Review 2 ==> Mid-term update4) 25 % ==> Review 3 ==> Final project presentation5) 25 % ==> Final report (In IEEE Conference/Journal format)

No Class TAs : Familiarity with CAD tools at the E3 238 Level compulsory.

Text: No textbook: Please take notes in class, or make backup arrangements.Recommended references:1) RF Microelectronics by B. Razavi (Pearson)2) The Design Of CMOS Radio-Frequency Integrated Circuits by T. Lee

(Cambridge University Press)

Tentative Calendar: On Class Website.

Administrative Matters

Course ContentsSystem Level Concepts:

Noise and Linearity. Concepts such as noise figure, 2-port noise parameters, IIP3. Cascaded noise figure and IIP3. The modeling of an RF system using these concepts. Receiver and Transmitter Architectures.

Circuit Design: • RLC Networks, • Low Noise Amplifiers & Mixers• Voltage Controlled Oscillators • Phase Locked Loops and Synthesizers• Power Amplifiers

Case Studies:• Cellular Transceiver• Wireless LAN transceiver• Millimeter wave transceiver

Addressing Past FeedbackThe Project in this course requires knowledge of some concepts that are introduced later in the semester -> This is the whole idea of a project in an advanced course. You

will need to study many things on your own. I am there to help if you need it.

Some of the material is too advanced->This is not a core course with compulsory enrolment. Please

decide if this is the right course for you.

We have other courses, the expectations are too high!-> The expectations are in line with similar courses elsewhere in

the world. The contents and/or project cannot be “dialled down”. Please decide if this is the right course for you.

Will this course prepare me for a research career in this area?-> This course is routinely taken by Ph.D. students enrolled in

IISc. My own Ph.D. advisees have used this course as a stepping stone in their research.

Connection to other courses

E3 284: Digital VLSI Circuits

E3 yyy: ICs for Wireline Commn.

E3 zzz: ICs for Data Conversion

E8 242: RF ICs and Systems

• Prerequisite: If you wish to take this course for credit and have not taken E3 238, you need to take my permission.

• It is recommended that students take the Digital VLSI Circuits course (Prof. Chetan Singh Thakur) and the RF Systems Course (Prof. Vinoy).

E3 237:ICs for Wireless Commn.

E3 238: Analog VLSI Systems

Frequencies and Applications

1 GHz 10 GHz 100 GHzBluetooth

802.11a WLAN

UWB

GSM/CDMA850

GSM/CDMA1900

GPS60 GHz 802.15.3.3c

77 GHz Radar

Sub-THz imaging

• Many commercial applications span the 1-10 GHz frequency range.

• Higher f T s are pushing CMOS radios to higher frequencies, traditionally the domain of SiGe or III-V semiconductors

• Many interesting research problems, plenty of employment !!!

24 GHz Radar

VHF/UHF Broadcasting

Commercial CMOS Products

0.35 um 0.25 um 0.18 um 0.13 um 65/45/32…14nm

An informal look at wireless

An iPod-nano Teardown....

http://techon.nikkeibp.co.jp/english/NEWS_EN/20081016/159685/

..reveals many chips inside...

... including a Wireless LAN chip by Broadcom...

A more scientific look

A Broadcom 2.4 GHz WLAN Transceiver

S. Khorram et. al., “A Fully Integrated SOC for 802.11b in 0.18-m CMOS”, IEEE J. Solid State Circuits, Dec. 2005. (Broadcom Paper)

• Architecture: zero-IF with on-chip LPF for channel selection. Super-heterodyne/low-IF architecture not chosen due to filter constraints.

• Gain = 88 dB, BW = 8 MHz, Noise Figure = 4.8-5.8 dB, excluding T/R switch

• Integrated PA, T/R switch, RF Baluns and Baseband MAC

The Receiver

LNA with on-chip balun

Wideband RSSI for blocker estimation

Narrowband RSSI for gain selection

Active Gilbert mixer

5th order Active RC LPF

8-b pipelined ADC

The Transmitter

Class AB stage with balun for SE 50-Ohm output

Current steering DAC for TX I/Q inputFiltering of Data

Converter image frequency

SSB mixers for up-conversion

The Local Oscillator

Crystal oscillator for Reference generation

Integer-N frequency synthesis

Receiver Front-end

5th order Active RC LPF – 8 MHz BW

LNA – Dominates RX Noise Figure

Programmable baseband Amplifiers

Received Signal Strength Indicators

88 dB RX gain with 8 MHz BW 6-7 dB Noise Figure with T/R switch included

Transmitter Front-end

1-dB compression point Max. TX output power = 13 dBm

I/Q mismatch causes EVM increase

Out of Band Power due to Harmonics and Spurs in LO

LO Generation and Distribution

Integer-N frequency synthesis

1.6 GHz VCO used to generate 2.4 GHz output – avoids LO Pulling1 MHz

channel spacing

1.6 GHz divided to 800 MHz and mixed with itself –provides 2.4 GHz. Spurs at 800 MHz and 4 GHz

Tuned buffers needed in LO distribution

Low Noise Amplifier

SE/Differential Conversion: Attenuation causes NF increase

Source degeneration for input match

Cascode input stage for gain, isolation, high frequency performance

Tuned output loads

Power AmplifierMeasure signal strength and adjust pre-amp gain

Pseudo-differential cascodes

Transformer coupled, tuned output stage

Gate-biasing for optimum linearity

Key Transceiver Data: Receiver Fix PER at 8% for different data rates

• RX sensitivity = -88 dBm for 11 Mbps, -93 dBm for 2 Mbps• Noise figure can be deduced from these sensitivity values

IIP3 = -15 dBm for high gain, 6 dBm for low gain

• Noise Figure dominates performance at the lower end of the dynamic range• Nonlinearities and non-ideal LO behavior dominates the higher end of the dynamic range

Key Transceiver Data: Transmitter

Spectral Mask Compliance

EVM Margin

What it Looks Like: The die-shot

Performance Summary