ECE 3113 INTRODUCTION TO RF

CIRCUIT DESIGN Lecture Notes for A-term 2016

LECTURE 1 Prof. R. Ludwig

Department of Electrical and Computer Engineering Worcester Polytechnic Institute

Worcester, MA copyright © 2016, R. Ludwig

Copyright, 1998 © R. Ludwig

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Objectives

• Motivation – why this course? • Organization/HWs/Exams • What differentiates low from high

frequency circuits?

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ECE 3113: Lecture 1 • Importance of RF circuit design

– Wireless and wirebased communication technologies (growth in multi-band, multi-protocol transceivers and WLAN)

– global positioning systems (GPS) – ASIC/SoC designs (bus systems, digital logic exceeding 3GHz

clock speeds) – Autonomous car projects with radar systems: 70GHz, lasers:

24GHz, cellular networks (802.11p): 5.9GHz

• Why this course?? – lumped (KVL/KCL) circuit representation no longer applies!

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What do we mean by going from lumped to distributed theory?

• Example: INDUCTOR

Low-frequency

(lumped)

LjRZ ω+=

High-frequency

Z = ?

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Case in point: bondwires of RF power transistors

BLF4G22-100 is a silicon LDMOS (Laterally Diffused Metal-Oxide-Semiconductor) power FET made by Philips. It is designed for Wideband Code Division Multiple Access (W-CDMA) cellular base station applications in the frequency range of 2.0-2.2 GHz. The device is rated for 24 W average output power and 150 W peak power. It operates at a nominal drain-source voltage of 28 V and delivers up to 13.5 dB of gain.

By permission of K. Vennema, NXP, Cumberland, RI, 2014.

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Current and voltage vary spatially over the component size

Upper MHz to GHz range

-1-0.5

00.5

1x-1

-0.5

0

0.5

1

y0

2

4

6

z

-1-0.5

00.5

1x

E (or V) and H (or I) fields

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Frequency spectrum • RadioFrequency (RF)

– TV, wireless phones, GPS – 300 MHz … 3 GHz operational frequency – 1 m … 10 cm wavelength in air

• MicroWave (MW) – RADAR, remote sensing – 8 GHz … 80 GHz operational frequency – 3.75 cm …3.75 mm wavelength in air

• Optical Communication – Typically above 100 GHz – Potential fibre bandwidth at 1550 nm: >30THz! – Electro-optical modulation: 100GHz

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Design Focus Cell phone transceiver circuit

Typical frequency ranges:

• 890 - 960 MHz (GSM)

• 824 – 894 MHz

• 1.9 – 2.5 GHz

(CDMA, WCDMA)

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Implementation • matching networks

• BJT/FET active devices

• biasing circuits

• printed circuit board

• mircostripline realization

• LTCC/HTCC technology

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New ways of RF integration

Low temperature co-fired ceramics can stack up to 50 layers of tape that are subsequently cured.

by permission: Lamina Ceramics

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Example: LNA design

Network analyzer for performance characterization

Conventional PCB implementation with SMA connectors