1

Radiofrequency Electronic Systems(2018-2019)

Instructors:

Prof. Pasquale Tommasino

Prof. Stefano Pisa

lessons timetable

- Monday 12.00-14.00 classroom 6

- Tuesday 10:00-12.00 classroom 6

- Wednesday 12.00-14.00 classroom 6

- Thursday 10.00-12.00 classroom 6

9 CFU - 12 weeks (≈90 hours)

2

TEACHING

is not

FILLING

a Bucket

LIGHTING

a Fire

BUT

Ask questions, stop me

I like when this happens for at least two reasons.

First, one of the key things you want to happen in teaching is to activate the students' curiosity. When students ask questions means that they're really engaged with the material.

Second, questions from students often don't necessarily have a single "right" answer. So when someone asks a question that's verychallenging, it's often a great opportunity to turn it back around on the class as a basis for discussion to try to make sense of a particularly difficult problem.

3

How will a professor react when asked a question he can't answer?

Bad professor: dodges the question or becomes angry.

Mediocre professor: promises to answer the question next class and never does.

Good professor: asks the class if anyone else knows; returns in the next class with an answer.

RF/microwave SystemsDenominations Frequency Interval GHz (109 Hz)

HF 0.003 - 0.030

VHF 0.030 - 0.300

P (Previous) UHF 0.300 - 1.000

L (Long) Band 1.0 - 2.0

S (Short) Band 2.0 - 4.0

C (Compromise) Band 4.0 - 8.0

X (Cross*) Band 8.0 - 12.0

Ku ( Under K) Band 12.0 - 18.0

K Band 18.0 - 26.5

Ka (Above K) Band Ka 26.5 - 40.0

Q Band 40.0 - 50.0

V Band 50.0 - 75.00

millimeter 40.0 - 300.0

Terahertz > 300.0

*Used in WW II for fire control, X for cross (as in crosshair).

4

Discrete Component CircuitsPDIP (Plastic Dual Inline Package)

SMD (Surface-Mounted Device)

Digital TV Transmitter

In Europe Digital Video Broadcast - Terrestrial (DVB-T)

Frequency division multiplexing with orthogonal codes (COFDM)

with 16-QAM or 64-QAM. DVB-S (satellite)

United States

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DVB-S Receiver

(DVB-S) Uplink 14-14.5 GHz Downlink 10.95 – 12.75 GHz (500 MHz)

RHCP (Right-Hand Circular Polarization) and LHCP polarizations

Terrestrial Receiver-Transmitting(TX/RX) System

(analog signal 2 -13 GHz)

Base-Band signal

Frequency Modulator

Amplifier mixer

Local Oscilaltor

Power Amplifier

Transmitter Antenna

Base-Band Signal

Frequency Demodulator

mixer

Local Oscilaltor Intermediate Frequency Amplifier

Receiving Antenna

Local Oscillator

6

Satellite Transponder(digital signals)

QPSK Demodulator

mixer

Local Oscillator

Intermediate Frequency Amplifier

Receiver Antenna Low-Noise

Amplifier

Rigenerator

Local Oscilaltor

Power Amplifier

Transmitting Antenna

QPSK Modulator

fIN

fOL1 fIN

fOL

Directional Coupler 3 dB Hybrid

Transmitting and Receiving Antenna Microwave

Source Continous Wave

(DRO)

mixer

Doppler Frequency

Body

v(t) = V0 sen(0t) v(t) = V1 sen(1t)

Filter

vIF(t)

Vout(t)

Doppler Radar

7

𝑅 =𝑐02· 𝑇 ·

𝑓𝐵𝐵

FMCW Radar

Course Outline

• INTRODUCTION: Examples of telecommunication and radar systems, example of a project.

• RF OSCILLATORS: resonant circuits, factors of merit and loss, examples of RLC networks, frequencystability coefficient, quartz as a circuit element, phase noise; Colpitts and quartz oscillators. Negative resistance oscillators: steady state and triggeringconditions, dielectric resonator oscillators, ceramicresonator oscillators.

8

• RF AMPLIFIERS: stability, stability circumferences, Rollet factor, Nyquist method, transducer gain evaluation. Amplifiers for maximum gain: design based on unconditionally stable transistors, lumped-distributed matching networks implementation, design based on conditionally stable transistors, design of stabilization networks, design in the stable region. Noise Figure, Low noise amplifiers, design for the minimum noise figure. Power amplifiers, parameters and classes of amplifiers, design of class A power amplifiers. Design starting from non-linear models and from load-pull measurements.

• RF FILTERS: Design of RF filters based on the “low-pass prototype” method, design of low-pass high-pass and band-pass filters. Low pass filter realization with microstrips.

• RF MIXER: characteristic parameters of Mixer, mixers with transistors: BJT, JFET. Mixer with diodes: non-linear model of the schottky diode, causes and patterns of noise in diodes, single diode mixer, balanced mixers.

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• IF amplifier and gain control.

• PLL (phase-locked loop) : operating principle, response to a phase and frequency error, stability, design of a PLL.

• Modulators and Demodulators: AM Modulators and demodulators, SSB, frequency modulators

• CAD (computer aided design) Laboratory: Examples with Microwave Office, of all the described circuits.

The following CAD examples will be presented:

1. design of matching networks and RLC circuits;

2. design of oscillators (Colpitts, Quartz, Ceramic);

3. design of amplifiers (maximum gain, and power amplifiers);

4. design of filters with lumped and distributed elements.

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RF ELECTRONIC SYSTEMSHF VHF-UHF MICROWAVES

OSCILLATOR COLPITTS

QUARTZ

COLPITTS

CRO

CRO

DRO

AMPLIFIERS

High Gain Elettronics II Elettronics II REACTIVE

MATCHING

Low Noise Elettronics II Elettronics II REACTIVE

MATCHING

High Power HF

TRASFORMER

VHF UHF

TRASFORMERREACTIVE

MATCHING

MIXER Schottky Diodes

Diplexer

TRANSISTORS

Schottky Diodes

Diplexer

TRANSISTORS

SCHOTTKY DIODES

180° Hybrid

TRANSISTORS

FILTERS LUMPED LUMPED (SMD) MICROSTRIP

MODULATOR, DEMODULATOR

CAD EXERCICES (MICROWAVE OFFICE) ALL THE DESCRIBED CIRCUITS

Course MaterialTextbook:

• Lecture notes available on the web site:

http://mwl.diet.uniroma1.it/people/pisa/RFELSYS.html

Recommended textbooks:

• 1. Kikkert_RF_Electronics_Course

• 2. David M. Pozar, Microwave Engineering, Fourth Edition

• 3. H.L. Krauss et al., Solid State Radio Engineering

• 4. Guillermo Gonzalez, Microwave Transistor Amplifiers

Web sites:

• 1. https://www.rf-microwave.com/en/home/ (italian supplier of RF components)

• 2. http://www.awrcorp.com/products/microwave-office

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awrde_v14_02_9226_5_64bit

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Grading

Your course grade will be determined as follows:

35% : Oral exam on one topic covered by Prof. Tommasino lectures

35% : Oral exam on one topic covered by Prof. Pisa lectures

30% : MWO project work

Design of RF Circuits1) Design Specifications

2) Dimensioning (Analytical, Smith's Chart, etc.)

3) Layout (CAD)

4) Optimization (CAD)

5) Prototype Realization (Milling Machine, ChemicalEtching)

6) Prototype Measurement

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Filter design Specifications

• Low Pass Filter

• maximally flat

• Cut-off Frequency, fC = 5.5 GHz

• Cut-off Attenuation, Ac= 3dB

• Out of band Attenuation = 10 dB at 7 GHz

Dimensioning (Ideal)low pass prototype method

Filter Elements N = 5g1=0.618, g2=1.618, g3=2, g4=1.618, g5=0.618

CAP

C=

ID=

0.358 pF

C1 CAP

C=

ID=

1.157 pF

C2

CAP

C=

ID=

0.358 pF

C3

IND

L=

ID=

2.341 nH

L1 IND

L=

ID=

2.341 nH

L2 PORT

Z=

P=

50 Ohm

1

PORT

Z=

P=

50 Ohm

2

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Dimensioning Results

4 5 6 7 7.5

Frequency (GHz)

1 Risposta in Ampiezza

-30

-20

-10

0

5.5 GHz -3.02

5.5 GHz -2.93

DB(|S[2,1]|)

1 Binomiale

DB(|S[2,1]|)

2 Chebychev

Physical Dimensioning

MSUB

Name=

ErNom=

Tand=

Rho=

T=

H=

Er=

RO1

3.38

0.0027

0.7

0.035 mm

0.508 mm

3.38

MLIN

L=

W=

ID=

0.910 mm

w15 mm

TL1 MLIN

L=

W=

ID=

5.872 mm

w75 mm

TL2 MLIN

L=

W=

ID=

2.947 mm

w15 mm

TL3 MLIN

L=

W=

ID=

5.872 mm

w75 mm

TL4 MLIN

L=

W=

ID=

0.910 mm

w15 mm

TL5 MLIN

L=

W=

ID=

20 mm

w50 mm

TL6 MLIN

L=

W=

ID=

20 mm

w50 mm

TL7 MSTEP

W2=

W1=

ID=

w15 mm

w50 mm

TL8 MSTEP

W2=

W1=

ID=

w75 mm

w15 mm

TL9 MSTEP

W2=

W1=

ID=

w15 mm

w75 mm

TL10 MSTEP

W2=

W1=

ID=

w75 mm

w15 mm

TL11 MSTEP

W2=

W1=

ID=

w15 mm

w75 mm

TL12

MSTEP

W2=

W1=

ID=

w50 mm

w15 mm

TL13 PORT

Z=

P=

50 Ohm

1

PORT

Z=

P=

50 Ohm

2

w50=1.161

w15=5.844

w75=0.544MLIN

L=

W=

ID=

0.910 mm

w15 mm

TL1 MLIN

L=

W=

ID=

5.872 mm

w75 mm

TL2 MSTEP

W2=

W1=

ID=

w75 mm

w15 mm

TL9 w15=5.844

w75=0.544

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Physical Dimensioning Results

4 5 6 7 7.5

Frequency (GHz)

Realizzazione Fisica

-15

-10

-5

0

5.12 GHz -3

5.5 GHz -4.72

DB(|S[2,1]|)

5 Realizzazione Fisica

DB(|S[2,1]|)

1 Binomiale

because of the steps, there is a noticeable deviation from the ideal behavior

CAD Optimization

4 5 6 7 7.5

Frequency (GHz)

Realizzazione Fisica

-15

-10

-5

0

7 GHz -10.4

5.5 GHz -2.99

DB(|S[2,1]|)

1 Binomiale

DB(|S[2,1]|)

6 Layout

Goal: Attenuation greater than 10 dB at 7 GHzVariables: Line lengthOptimization methods: Random + Gradient

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Layout