Newcom Department 3İstanbul Meeting

6 September 2004 

Işık University, İstanbul

Participating Partners

• POLITO (Giovanni Ghione)

• Chalmers (Thomas Eriksson)

• UU (Erik Öjefors)

• ISIK (Ahmet Aksen, Sıddık Yarman)

• Bilkent (Abdullah Atalar, Tarık Reyhan)

Excused: CTTC, TUI and UoP

Meeting Agenda• Welcome, agreement on agenda• Overview and status of WPR3 activities• Discussion on Deliverable DR1• Discussion on future actions/activities to make

WP3 successful• Workshop:

– Lecture by Giovanni Ghione on “Nonlinearity characterization and modeling”

– Lunch

Meeting Agenda (cont.)

• Workshop continued:– Lecture by Thomas Eriksson on “it++”– Tea/coffee break– Lecture by Erik Öjefors on “Integrated

antennas”– Tea/coffee break– Lecture by Sıddık Yarman on “Impedance

matching and modeling using real frequency techniques”

Overview and status of WPR3 activities

• Kickoff meeting of Leuven, 18 June 2004• Eight partners participated and made

presentations to describe their research areas• 4 clusters formed:

– Nonlinearity of power amplifiers (Chalmers, POLITO, Bilkent, UoP, ISIK, CTTC)

– Antennas (UU, TUI, CTTC, ISIK)– Phase Noise (Bilkent, Chalmers, POLITO)– RFIC Front ends (UoP, UU, TUI)

Overview and status of WPR3 activities (cont.)

• A mail reflector is formed: wpr3@lists.bilkent.edu.tr

• A web page is prepared: www.ee.bilkent.edu.tr/~newcomd3 (contains the presentations of kickoff meeting)

Overview and status of WPR3 activities (cont.)

• it++ developed by Chalmers can be a common ground (GNU License)– This afternoon Thomas Eriksson of Chalmers will

make a presentation on it++

Overview and status of WPR3 activities (cont.)

• 2 partners (Supelec and PUT) are not participating)

Discussion on future actions/activities to make WP3

successful

Discussion on future actions/activities to make WP3

successful

• Our success will be measured by the Degree of integration

Discussion (cont.)

• Degree of integration is measured by– Number of PhD students in training

activities– Number of PhD students in exchange

programs– Number of people in NEWCOM workshops– Number of jointly submitted papers– Number of jointly supervised PhD students

Discussion (cont.)• Degree of integration is measured by

– Number of commonly evaluated PhD theses– Number of joint patents– Number of partners providing shared

equipment– Number of other students participating in

exchange

PhD Student Exchange

• Housing cost is provided by NEWCOM• Which partners can accept students?• Which partners can provide students?• For how long? • Difficulty of sending a student to

another place (is it just a lost time for the sending institution?)

• Is language a problem?

Deliverable DR1

• DR1 date is delayed by 1.5 months• To be prepared:

– Related publications with abstracts– Related patents– Completed/ongoing projects– Available measuring equipment,

design/analysis software– Courses given on related areas (with

detailed syllabus, language of instruction)

Deliverable DR1 (cont.)

– Required know-how to complete WPR3 objectives

– Identification of gaps among WPR3 participants (needs to be done through four clusters)

– Detailed plan for encountering gaps (needs to be done through four clusters)

• So far 3 partners provided the contributions (TUI, UU, ISIK)

NEWCOM WPR3 Workshop

Nonlinearity of power amplifiers

• Nonlinearity?– At the input f1

– At the output (f1) (2f1) (3f1) (4f1) ….(nf1)

– Relatively easy to filter if system bandwidth is not too big.

Nonlinearity of power amplifiers

• Why is it important?– Modern communication systems use

multicarriers.

– At the input: f1 + f2

– At the output: (mf1 + nf2) (m+n th order)

– Among them most troublesome: 3rd order (IM3)2f1 - f2 or 2f2 - f1

Nonlinearity of power amplifiers

• IM3 Example:– f1 + f2 : 2420 MHz + 2430 MHz

– 2f1 - f2 : 2410 MHz

– 2f2 - f1 : 2440 MHz

Nonlinearity of power amplifiers

• Typical power amplifer operates in Class A or Class AB. (In Class AB amplifier’s DC current increases with increasing drive).

• What can be done to reduce nonlinearity?– Use the power amplifier at a lower signal level

or with a higher bias at the expense of reduced efficiency

– Use predistortion/linearization methods

Linearization techniques

Feedforward Linearization Cartesian Feedback RF Predistortion Digital Predistortion

Nonlinearity of power amplifiers

• Predistortion/cancellation methods are expensive or are not very efficient: Suitable for base stations

• For mobile systems efficiency is very important.

• Comprimise between efficiency and linearity: Bias as low as possible to increase efficiency, sufficiently high to reduce IM3

Nonlinearity of power amplifiers

• State-of-the-art: What is done?– Each device is measured for allowable IM3 at

each channel– Input level and bias is adjusted to satisfy the

specs for highest efficiency– Input level and bias values are stored in a

lookup table that contains also temperature variations

Giovanni Ghione

• Professor of Politecnico di Torino– Book: Noise in semiconductor devices:

Modeling and simulation

• Nonlinearity characterization and modeling

it++ Presentation

• Thomas Eriksson of Chalmers University of Technology, Göteborg

Integrated antennas

• Erik Öjefors of University of Uppsala

Impedance matching and modeling using real frequency

techniques

• Sıddık Yarman of Işık University