Design Basics on Power Amplifiers

Wednesday, 16th December 2015

Pascual D. Hilario Re

Outline1. Introduction2. Design3. Manufacturing4. Results5. Conclusions and Future work

What is amplification?

1. Introduction

3

The operation of an electronic device increasing the power of a signal.

Amplifiers depending on operating frequency

1. Introduction

4

Low frequency High frequency or RF

Transistor

Inpu t MatchingNetwork

Outpu t MatchingNetwork

Bias Network(Gate)

Bias Netwo rk(Drain)

RF in

RF out

VgsVds

1. Introduction

5

Basic Microwave Amplifier scheme

1. Introduction

6

Main concepts to work with:

• Linearity: capability of an amplifier to reproduce

increased exact copies of the input signal.

• Efficiency: how much of the DC power supplied to the

amplifier is transformed into amplification.

They are in inverse proportion.These characteristics determine the class of the amplifier!

Transistor Characteristic IV Curves

1. Introduction

7

𝑉 𝐶𝐸

𝐼𝐶

𝐼𝐵=100𝜇 𝐴10𝑚𝐴

C (Collector) or D (Drain)

E (Emitter) or S (Source)

B (Base) or G (Gate)

V

+ _

𝑉 𝐶𝐸

𝐼𝐶

𝑰 𝑩

Load-line

1. Introduction

8

DC equivalent

AC equivalent

𝑉 𝐶𝐸

𝐼𝐶

𝑉 𝐶𝐶−𝑉 𝑅𝐶−𝑉 𝐶𝐸−𝑉 𝑅𝐸

=0

𝑉 𝐶𝐶− 𝐼𝐶 𝑅𝐶−𝑉 𝐶𝐸− 𝐼𝐸 𝑅𝐸=0

𝑉 𝐶𝐶− 𝐼𝐶 (𝑅¿¿ 𝐶+𝑅𝐸)−𝑉 𝐶𝐸=0¿

Load-line equation (y = mx+n):

𝐼𝐶=−1

𝑅𝐶+ 𝑅𝐸𝑉 𝐶𝐸+

𝑉 𝐶𝐶

𝑅𝐶+𝑅𝐸

In saturation… Cut-off… 𝑉 𝐶𝐶

𝑅𝐶+𝑅𝐸

𝑉 𝐶𝐶

Q-Point

DC Load-line

Load-line

1. Introduction

9

DC equivalent

AC equivalent

𝑣𝐶𝐸=−𝑖𝐶𝑟 𝐶

𝑉 𝐶𝐸−𝑉 𝐶𝐸𝑄=− ( 𝐼𝐶− 𝐼𝐶𝑄)𝑟𝐶

Load-line equation (y = mx+n):

𝐼𝐶=− 1𝑟𝐶

𝑉 𝐶𝐸+𝑉 𝐶𝐸𝑄

𝑟 𝐶+𝐼𝐶𝑄

𝑖𝐶

𝑉 𝐶𝐸

In saturation… In Cut-off…

Q-Point

𝑰 𝑪𝑸+𝑽 𝑪𝑬𝑸

𝒓 𝑪

𝑽 𝑪 𝑬𝑸+ 𝑰𝑪𝑸𝒓 𝑪

𝐼𝐶

AC Load-line

Load-line

1. Introduction

10

Q-Point

𝑰 𝑪𝑸+𝑽 𝑪𝑬𝑸

𝒓 𝑪

𝑽 𝑪 𝑬𝑸+ 𝑰𝑪𝑸𝒓 𝑪 𝑉 𝐶𝐸

𝐼𝐶

AC Load-line

𝑣 𝐶𝐸

/𝐷𝑆≡

𝑣 𝑅𝐹 𝑜

𝑢𝑡

𝑖𝐶𝐸 /𝐷𝑆≡𝑖𝑅 𝐹𝑜𝑢𝑡

𝑖 𝐵≡𝑖 𝑅

𝐹 𝑖𝑛

𝑣 𝐺𝑆≡𝑣 𝑅

𝐹 𝑖𝑛

or

Power Amplifier Classes

1. Introduction

11

Class Conduction Angle

A θ = 2π

AB π < θ < 2π

B θ = π

C θ < π

D – T θ ≈ 0

Power Amplifier Classes

1. Introduction

12

Clase A Clase B

Clase AB Clase C

Power Amplifier Classes

1. Introduction

13

Outline1. Introduction2. Design3. Manufacturing4. Results5. Conclusions and Future work

Transistor Tecnology Selection• GaN HEMT:

High Efficiency High Gain Great Bandwidth Low Power Consumption

Selección del Transistor

• CGH40010F (Cree Inc.)

2. Design

15

IV Characteristics and Q-Point

2. Design

16

0 30 60 84Vds (V)

IV Curves

0

500

1000

1500

2000

2400

Ids

(mA

)

IV Curves (mA)

Q-Point (28V, 482mA)

S.O.A.

TrVi Ii

S

1 2

3

4 5 6

CGH40010F_R6_VAID=Q1Tbase=25Rth=8

Swp Step

IVCURVEID=IV1VSWEEP_start=0 VVSWEEP_stop=84 VVSWEEP_step=1 VVSTEP_start=-10 VVSTEP_stop=2 VVSTEP_step=0.2 V

• Maximum drain voltage (84 V)• Maximum drain current (1500 mA)• Cut-off threshold (67 mA)• Saturation threshold• Maximum dissipated power (14 W)

Dynamic/AC Load-line

2. Design

17

TrVi Ii

S

1 2

3

4 5 6

CGH40010F_R6_VAID=Q1Tbase=25Rth=8

0.000399 mA

-2.2 V

482 mA

28 V

482 mA0 V

0 mA27.7 V

482 mA0 V

0 mA107 V

I_METERID=Id_intr

482 mAV_METERID=Vd_intr

DCVSID=VgsV=-2.2 V

0.000398 mA-2.2 V

I_METERID=I_in

0 mA

0 V

0 V

I_METERID=Ig

0.000399 mA

-2.2 V

DCVSID=VdcV=28 V

482 mA28 V

V_METERID=Vd

I_METERID=Id

482 mA

28 V

3:Bias

12

LTUNER2ID=TU3Mag=0Ang=0 DegZo=50 Ohm

0.000399 mA0 mA

0.000398 mA

3:Bias

1 2

LTUNER2ID=TU1Mag=0Ang=0 DegZo=50 Ohm

482 mA 0 mA

0 V

482 mA

V_METERID=VM_trise

PORTP=2Z=50 Ohm

0 mA

PORT_PS1P=1Z=50 OhmPStart=0.6 dBmPStop=40.6 dBmPStep=1 dB

0 mA

PORT1P=1Z=50 OhmPwr=27.6 dBm

Conn_Vi

27.7 V

Conn_Vi

27.7 V

Conn_Ii

0 V

Conn_Ii

0 V

0 30 60 84Vds (V)

IV Curves

0

500

1000

1500

2000

2400

Ids

(mA

)

28 V482.3 mAVstep = -2.2 V

IV Curves (mA)

DLL @ 7.6dBm (mA)

DLL @ 17.6dBm (mA)

DLL @ P1dB (mA)

0 0.3 0.6 0.816Time (ns)

RF in VS. RF out

-600

-400

-200

0

200

400

600

P1d

B In

put

Pow

er

-300

-200

-100

0

100

200

300

20dB

m I

nput

Pow

er

RF IN @ 20dBm (mA)

RF OUT @ 20dBm (mA)RF IN @ P1dB (mA)

RF OUT @ P1dB (mA)

DCVSID=VgsV=-2.2 V

0.000398 mA-2.2 V

I_METERID=I_in

0 mA0 V

0 V

I_METERID=Ig

0.000399 mA-2.2 V

3:Bias

12

LTUNER2ID=TU3Mag=0Ang=0 DegZo=50 Ohm

0.000399 mA0 mA

0.000398 mA

Gain, Output Power and PAE

2. Design

18

0.6 10.6 20.6 30.6 40.6Power (dBm)

Pin VS Pout and Gain

0

10

20

30

40

50

27.6 dBm10.9 dB

18.52 dBm11.89 dB

Pout (dBm)

PGain (dB)

PAE (%)

Stability

• Critical factor in order to avoid oscillations ()

• This is due to the negative either input or output resistance

2. Design

19

𝑅𝑒 {𝑍𝑆+𝑍 𝑖𝑛}<0 𝑅𝑒 {𝑍𝑜𝑢𝑡 +𝑍 𝐿 }<0

TransistorInput Matching Network

Output Matching Network

S in out L

0Z

0Z

𝑍=𝑍 01+Γ1− Γ

Conditional Stability

Stability• Border which delimits between stable and unstable

regions:

2. Design

20

|Γ 𝑖𝑛|>1 |Γ 𝑖𝑛|<1

|Γ 𝑖𝑛|>1|Γ 𝑖𝑛|<1

Unconditional Stability Unconditional Unstability

Stability• Border which delimits between stable and unstable

regions:

2. Design

21

|Γ 𝑖𝑛|>1

|Γ 𝑖𝑛|<1

|Γ 𝑖𝑛|<1

|Γ 𝑖𝑛|>1

Stability2. Design

22

0 1.0

1.0

-1.0

10.0

10.0-10.0

5.0

2.0

3.0

4.0

0.2

0.4

0.6

0.8

0.8

-0.8

Stability CirclesSwp Max

1

Swp Min-1

Input Circle

Output Circle

• Stability circles @ → Potentially unstable

• Dashed lines → Unstable region

Stability Factor: K-Δ Test

• It is convenient to have a design with in a reasonable BW

2. Design

23

Stabilization methods

2. Design

24

50 2050 4050 6050 8050 10000Frequency (MHz)

Initial K Factor

0

2

4

6

8

2450 MHz4.424

2450 MHz0.5643

K (no resistor)

K (gate resistor)

0 1.0

1.0

-1.0

10.0

5.0

2.0

3.0

4.0

0.2

0.4

0.6

0.8

Stability Circles before stabilizationSwp Max3000MHz

Swp Min2000MHz

Input Stability Circles

Output Stability Circles

0 1.0

1.0

-1.0

10.0

5.0

2.0

3.0

4.0

0.2

0.4

0.6

0.8

Stability Circles after stabilizationSwp Max3000MHz

Swp Min2000MHz

Input Stability Circles

Output Stability Circles

Unilateral Approximation

2. Design

25

𝑈=| 𝑆11𝑆12𝑆21𝑆22

(1−|𝑆11|2 ) (1−|𝑆22|

2 )|−20 log (1+𝑈 )<𝐺𝑇 −𝐺𝑇𝑈 (𝑑𝐵 )<−20 log (1−𝑈 )

Maximum gain design. Bilateral case:

Γ 𝐼𝑁=𝑆11+𝑆12𝑆21𝚪𝑳

1−𝑆22𝚪𝑳=Γ𝑆

∗

Γ𝑂𝑈𝑇=𝑆22+𝑆12𝑆21𝚪𝑺

1−𝑆11𝚪𝑺=Γ 𝐿

∗

Maximum gain design. Unilateral case:

Γ 𝐼𝑁=𝑆11=Γ 𝑆∗

Γ𝑂𝑈𝑇=𝑆22=Γ 𝐿∗

2-Port Device11S 22S

21S

?012 S

−3.7225 𝑑𝐵 ¿ 𝐺𝑇−𝐺𝑇𝑈 (𝑑𝐵 )<¿ 4.5775𝑑𝐵¿

Load-Pull

2. Design

26

Process whereby a set of points of the Smith Chart are evaluated in

terms of good performance as potential candidates to be the final

reflection coefficient for the Output Matching Network.

Load-Pull

2. Design

27

DCVSID=VDSV=28 VDCVS

ID=VGSV=-2.2 V

V_METERID=Vd

V_METERID=Vg

I_METERID=Ig

I_METERID=Id

Xo Xn. . .

SWPVARID=BiasVarName="iBias"Values=stepped(3,4,0.5)UnitType=None

Xo Xn. . .

SWPVARID=GammaL3VarName="iGammaL3"Values=stepped(-180,180,60)UnitType=None

Xo Xn. . .

SWPVARID=GammaL2VarName="iGammaL2"Values=stepped(0,360,90)UnitType=None

TrVi Ii

S

1 2

3

4 5 6

CGH40010F_R6_VAID=Q1Tbase=25Rth=8

3:Bias

12

LTUNER2ID=SourceTuner1Mag=0.5Ang=0 DegZo=50 Ohm

3:Bias

1 2

LTUNER2ID=LoadTuner1Mag=0.5Ang=0 DegZo=50 Ohm

PORTP=2Z=50 Ohm

PORT_PS1P=1Z=50 OhmPStart=0.600000000000001 dBmPStop=30.6 dBmPStep=1 dB

7

⦁ Attach gate / base current & voltage meters to desired device pin ⦁ Attach drain / collector current & voltage meters to desired device pins ⦁ Note that current should always defined into the desired pin

4

⦁ Set the Source Tuner to the desired impedance. ⦁ For 50 Ohms, set:

Mag1 = 0Ang1 = 0

2

⦁ Set power sweep ⦁ Disable power sweep by

replacing with PORT1

1

⦁ Enable / Disable SWPVAR blocks based on your needs ⦁ Set enabled SWPVAR sweep values ⦁ Do not change any swept variable names. ⦁ Contact technical support to sweep additional

variables

6

⦁ Replace with your DUT

iBias=3

iGammaL3=0iGammaL2=0

5

⦁ Replace DCVS with DCCS as needed

⦁ Do not delete any of the tuners or voltage and current meters; they are all needed for load pull simulation due to the switch to A/B wave file formats

⦁ It is okay to rename this schematic

3

⦁ Set schematic frequencies under schematic options

• AWR has its own script that automates the process

• Source-Pull is still in beta phase →

Load-Pull

2. Design

28

Once the Load-Pull has been performed, the points that agree with the design

specifications are chosen.

0 1.0

1.0

-1.0

10.0

10.0

-10.0

5.0

5.0

-5.0

2.0

2.0

-2.0

3.0

3.0

-3.0

4.0

4.0

-4.0

0.2

0.2

-0.2

0.4

0.4

-0.4

0.6

0.6

-0.6

0.8

0.8

-0.8

Output Matching NetworkSwp Max2.6e+009

Swp Min11.1

Desired MN Impedance (Ohm)

Obtained MN Impedances (from 2.3 to 2.6 GHz)

GTrans Contours

PAE Contours

Output Stab. Circle

LTUNERID=TU1Mag=0.44152Ang=149.3904 DegZo=50 Ohm

TLINID=50Z0=50 OhmEL=47 DegF0=2450 MHz

CAPID=C1C=50 pF

TLINID=TL1Z0=50 OhmEL=45 DegF0=2450 MHz

OPENID=J1

PORTP=1Z=50 Ohm

PORTP=2Z=50 Ohm

PORTP=3Z=50 Ohm

PORTP=4Z=50 Ohm

Γ 𝑜𝑢𝑡=0.44152∠149.3904 °

0 1.0

1.0

-1.0

10.0

10.0

-10.0

5.0

5.0

-5.0

2.0

2.0

-2.0

3.0

3.0

-3.0

4.0

4.0

-4.0

0.2

0.2

-0.2

0.4

0.4

-0.4

0.6

0.6

-0.6

0.8

0.8

-0.8

Load PullSwp Max51.2778

Swp Min11.1

12.008 dBr 0.409879x 0.152749

51.278 %r 0.395923x 0.261322

Max. PAE @ P1dB

PAE @ P1dB

Max. GTrans @ P1dB

GTrans @ P1dB

Output Stability Circle

LTUNERID=TU1Mag=0.44152Ang=149.3904 DegZo=50 Ohm

TLINID=50Z0=50 OhmEL=47 DegF0=2450 MHz

CAPID=C1C=50 pF

TLINID=TL1Z0=50 OhmEL=45 DegF0=2450 MHz

OPENID=J1

PORTP=1Z=50 Ohm

PORTP=2Z=50 Ohm

PORTP=3Z=50 Ohm

PORTP=4Z=50 Ohm

Load-Pull

2. Design

29

𝑍 𝑖𝑛=𝑍0𝑍𝐿+ 𝑗 𝑍0 tan (𝛽𝑙)𝑍 0+ 𝑗 𝑍𝐿 tan (𝛽𝑙)

01.0

-1.0

1.0

10.0

-1 0.0

10.0

5.0

-5 .0

5.0

2.0

-2 .02.0

3.0

-3 .0

3.0

4.0

-4 .0

4.0

0.2

-0.2

0.20.4

-0.4

0. 4

0.6

-0.6

0.6

0.8

-0.8

0.8

0 1.0

1.0

-1.0

10.0

10 .0

-10.0

5.0

5. 0

-5.0

2.0

2.0

-2.0

3.0

3.0

-3.0

4.0

4.0

-4.0

0.2

0.2

-0.2

0.4

0.4

-0.4

0.6

0.6

-0.6

0.8

0.8

-0.8

OMNSwp Max2450MHz

Swp Min2450MHz

Series TXLine

Open STUB

Γ 𝑜𝑢𝑡𝚪𝒐𝒖𝒕 Γ 1

𝚪𝟏

Input Matching Network

2. Design

30

0 1.0

1.0

-1.0

10.0

10 .0

-10.0

5.0

5. 0

-5.0

2.0

2.0

-2.0

3.0

3.0

-3.0

4.0

4.0

-4.0

0.2

0.2

-0 .2

0.4

0.4

-0.4

0.6

0.6

-0.6

0.8

0.8

-0.8

Input Matching NetworkSwp Max2.6e+009

Swp Min2.3e+009

2450 MHzr 1.14997e-005x -0.435895

2450 MHzr 0.159695x -0.366266

Desired MN Impedance (Ohm)Obtained MN Impedances (from 2.3 to 2.6 GHz)Input Stab. CircleAfter parallelOpen Stub

• Conjugate Matching

TLINID=TL2Z0=17.93 OhmEL=24.3 DegF0=2450 MHz

OPENID=J1

TLINID=TL1Z0=48.27 OhmEL=65.7 DegF0=2450 MHz

PORTP=1Z=50 Ohm

PORTP=2Z=50 Ohm

Bias Network

2. Design

31

• Critical design part in order to avoid RF leakage through the bias network.

• Many possible configurations:a. Low BWb. Acceptable BWc. Good BW and reduced size

Bias Network

2. Design

32

TrVi Ii

S

1 2

3

4 5 6

CGH40010F_R6_VAID=Q1Tbase=25Rth=8

I_METERID=Id1

V_METERID=Vd1

I_METERID=Ig1

CAPID=C2C=20 pF

I_METERID=I_in1

MLINID=TL6W=2.1394617455677 mmL=9.00788441856134 mmMSUB=RO_RO4350B1

MLINID=TL7W=1.13179 mmL=18.2827939523261 mmMSUB=RO_RO4350B1

MLINID=TL14W=1.13179 mmL=8.42648946346399 mmMSUB=RO_RO4350B1

MLINID=TL20W=1.13179 mmL=3.44366958458732 mmMSUB=RO_RO4350B1

MLINID=TL27W=1.13179 mmL=6.2 mmMSUB=RO_RO4350B1

MLINID=TL28W=1.13179 mmL=3.9182030314894 mmMSUB=RO_RO4350B1

MOPEN$ID=TL12MSUB=RO_RO4350B1

1 2

3

MTEE$ID=TL15MSUB=RO_RO4350B1

RESID=R1R=6.81 Ohm

1 2

1 2

GPROBE2ID=GP1

1 2

1 2

GPROBE2ID=GP2

V_METERID=Vd2

I_METERID=Id2

V_METERID=VM_triseFinal

12

3

MTEE$ID=TL13MSUB=RO_RO4350B1

CAPID=C5C=47000 pF

DCVSID=Vgs1V=-2.2 V

MLINID=TL4W=W_TLStub mmL=L_TL2Stub mmMSUB=RO_RO4350B1

MLINID=TL22W=1.09377006058279 mmL=1.0929717637931 mmMSUB=RO_RO4350B1

MLINID=TL23W=5 mmL=5 mmMSUB=RO_RO4350B1

MLINID=TL26W=1.11213944458008 mmL=2.49627311533999 mmMSUB=RO_RO4350B1

MSRSTUB2ID=ST1Ro=Ro_stub mmWg=Wg_stub mmW=W_TLStub mmTheta=Theta_stub DegMSUB=RO_RO4350B1

1

2

3MTEE$ID=TL9MSUB=RO_RO4350B1

MVIA1PID=V4D=1 mmH=0.52578 mmT=0.017 mmW=5 mmRHO=0.7MSUB=RO_RO4350B1

RESID=R2R=37.4 Ohm

MLINID=TL8W=W_TLStub mmL=L_TL1Stub mmMSUB=RO_RO4350B1

PORT_PS1P=1Z=50 OhmPStart=0 dBmPStop=40 dBmPStep=1 dB

PORT1P=1Z=50 OhmPwr=10 dBm

Conn_ViConn_Ii

Low Freq. Stabilization Resistor

Bypass Capacitor

Final design

2. Design

33

TrVi Ii

S

1 2

3

4 5 6

CGH40010F_R6_VAID=Q1Tbase=25Rth=8

I_METERID=Ig1

CAPID=C2C=20 pF

I_METERID=I_in1

MLINID=TL6W=2.1394617455677 mmL=9.00788441856134 mmMSUB=RO_RO4350B1

MLINID=TL7W=1.13179 mmL=18.2827939523261 mmMSUB=RO_RO4350B1

MLINID=TL14W=1.13179 mmL=8.42648946346399 mmMSUB=RO_RO4350B1

MLINID=TL20W=1.13179 mmL=3.44366958458732 mmMSUB=RO_RO4350B1

MLINID=TL27W=1.13179 mmL=6.2 mmMSUB=RO_RO4350B1

MLINID=TL28W=1.13179 mmL=3.9182030314894 mmMSUB=RO_RO4350B1

MOPEN$ID=TL12MSUB=RO_RO4350B1

1 2

3

MTEE$ID=TL15MSUB=RO_RO4350B1

RESID=R1R=6.81 Ohm

1 2

1 2

GPROBE2ID=GP1

V_METERID=Vd2

I_METERID=Id2

12

3

MTEE$ID=TL13MSUB=RO_RO4350B1

MLINID=TL4W=W_TLStub mmL=L_TL2Stub mmMSUB=RO_RO4350B1

MLINID=TL22W=1.09377006058279 mmL=1.0929717637931 mmMSUB=RO_RO4350B1

MLINID=TL26W=1.11213944458008 mmL=2.49627311533999 mmMSUB=RO_RO4350B1

MSRSTUB2ID=ST1Ro=Ro_stub mmWg=Wg_stub mmW=W_TLStub mmTheta=Theta_stub DegMSUB=RO_RO4350B1

1

2

3MTEE$ID=TL9MSUB=RO_RO4350B1

RESID=R2R=37.4 Ohm

MLINID=TL8W=W_TLStub mmL=L_TL1Stub mmMSUB=RO_RO4350B1

PORT_PS1P=1Z=50 OhmPStart=0 dBmPStop=40 dBmPStep=1 dB

PORT1P=1Z=50 OhmPwr=10 dBm

Conn_ViConn_Ii

CAPID=C1C=47 pF

CAPID=C4C=47000 pF

MLINID=TL1W=1.13179 mmL=9.1 mmMSUB=RO_RO4350B1

MLINID=TL2W=1.15424925832038 mmL=8.8091341147881 mmMSUB=RO_RO4350B1

MLINID=TL3W=1.13179 mmL=2.83546915660083 mmMSUB=RO_RO4350B1

MLINID=TL5W=W_DoubleStub mmL=L_DoubleStub mmMSUB=RO_RO4350B1

MLINID=TL11W=W_DoubleStub mmL=L_DoubleStub mmMSUB=RO_RO4350B1

MLINID=TL17W=1.13179 mmL=1.83798534101102 mmMSUB=RO_RO4350B1

MLINID=TL19W=1.13179 mmL=3.27959942836177 mmMSUB=RO_RO4350B1

MLINID=TL21W=W_TLStub mmL=L_TL2Stub mmMSUB=RO_RO4350B1

MLINID=TL25W=1.13179 mmL=2.36734037034666 mmMSUB=RO_RO4350B1

MLINID=TL29W=1.09977380371094 mmL=1.09910240478516 mmMSUB=RO_RO4350B1

MLINID=TL34W=W_TLStub mmL=L_TL1Stub mmMSUB=RO_RO4350B1

MOPEN$ID=TL10MSUB=RO_RO4350B1

MOPEN$ID=TL18MSUB=RO_RO4350B1

MOPEN$ID=TL33MSUB=RO_RO4350B1

MSRSTUB2ID=ST3Ro=Ro_stub mmWg=Wg_stub mmW=W_TLStub mmTheta=Theta_stub DegMSUB=RO_RO4350B1

12

3

MTEE$ID=TL16MSUB=RO_RO4350B1

1 2

3

MTEE$ID=TL24MSUB=RO_RO4350B1

1

2

3MTEE$ID=TL32MSUB=RO_RO4350B1

1 2

1 2

GPROBE2ID=GP2

1

2

3

4

MCROSSX$ID=MX1MSUB=RO_RO4350B1

PORTP=2Z=50 Ohm

W_DoubleStub=0.948360421001726L_DoubleStub=3.48189099549556

Input Matching Network

Output Matching Network

• Some changes were made after using real transmission lines

0 1.0

1.0

-1.0

10.0

5.0

2.0

3.0

4.0

0.2

0.4

0.6

0.8

Matching Networks ComparisonSwp Max

10

Swp Min-30

Mag 0.4531Ang 148.7 Deg

Mag 0.4151Ang 152 Deg

Mag 0.5691Ang -159.8 Deg

Mag 0.7377Ang -162.5 Deg

rhoS IDEAL

rhoS REAL

Input Stability Circle

rhoL IDEAL

rhoL REAL

Output Stability Circle

Final design

2. Design

34

• RO4350B substrate with low thickness to take care about termal conductivity

50 2050 4050 6050 8050 10000Frequency (MHz)

Rollet's Condition in Final Design

0

5

10

15

20

0

0.5

1

1.5

2K (L)

B1 (R)

2000 2200 2400 2600 2800 3000

Frequency (MHz)

S-Parameters of the PA

-35

-30

-25

-20

-15

-10

-5

0

-5

-1.429

2.143

5.714

9.286

12.86

16.43

20

2450 MHz

2506 MHz-10 dB

2392 MHz-10 dB

2450 MHz-27.67 dB

2450 MHz15 dB

S11(dB) (L)

S21(dB) (R)

S12(dB) (L)

S22(dB) (L)

0 10 20 30 40Power (dBm)

Comparison

0

5

10

15

20

Gai

n (d

B)

10

20

30

40

50

Pou

t (d

Bm

)

0

20

40

60

80P

AE

(%)

26.16 dBm

26.16 dBm40.16 dBm

26.16 dBm53.3

26.16 dBm14 dB

PAE After

PAE Before

Pout After (dBm)

Pout Before (dBm)

Gain(dB) After

Gain(dB) Before

2. Design

35

• RO4350B substrate with low thickness to take care about termal conductivity

Final design

RF OUTRF IN

Outline1. Introduction2. Design3. Manufacturing4. Results5. Conclusions and Future work

Heat Sink Selection

3. Manufacturing

37

𝜃 𝑗𝑎=𝜃 𝑗𝑐+𝜃𝑐𝑠+𝜃𝑠𝑎=𝑇 𝑗−𝑇 𝑎

𝑄 =14.8192º𝐶 /𝑊

𝜃𝑐𝑠=𝜌 ·𝑡𝐴 =0.5 º𝐶 /𝑊 (𝑇𝑦𝑝 .𝑖𝑛 h𝑡 𝑒𝑟𝑚𝑎𝑙 𝑐𝑜𝑚𝑝𝑜𝑢𝑛𝑑)

𝜃𝑠𝑎=𝑇 𝑗−𝑇𝑎

𝑄 −(𝜃 jc+𝜃𝑐𝑠)

𝜃 𝑗 𝑐=8.0 º𝐶 /𝑊 (𝑇𝑟𝑎𝑛𝑠𝑖𝑠𝑡𝑜𝑟 h𝐷𝑎𝑡𝑎𝑠 𝑒𝑒𝑡)

𝜃𝑠𝑎𝑀𝑎𝑥=6.31921 º𝐶 /𝑊

Heat Sink Selection

3. Manufacturing

38

𝜃¿ ¿

Assembly

3. Manufacturing

39

Assembly

3. Manufacturing

40

Outline1. Introduction2. Design3. Manufacturing4. Results5. Conclusions and Future work

4. Results

42

4. Results

43

2000 2200 2400 2600 2800 3000

Frequency (MHz)

S-Parameters of the PA

-35

-30

-25

-20

-15

-10

-5

0

-5

-1.429

2.143

5.714

9.286

12.86

16.43

20

2195 MHz 2450 MHz

Simulated S11(dB) (L)

Simulated S21(dB) (R)

Simulated S12(dB) (L)

Simulated S22(dB) (L)

Measured S11(dB) (L)

Measured S21(dB) (R)

Measured S12(dB) (L)

Measured S22(dB) (L)

• To correct the frequency shift:

4. Results Inconvenients and unexpected stuff

After 4 minutes working, the transistor was BURNT!

Potential causes:

a. Thermal compound

b. Q-Point too close to the maximum dissipation curve

c. Testing with LOW Input Power. LOW PAE. HIGH dissipation

d. When frequency shift occurs, at 2.45GHz we have a totally different behaviour

• IT HAS NOT BEEN POSSIBLE TO MEASURE ANYMORE

44

Outline1. Introduction2. Design3. Manufacturing4. Results5. Conclusions and Future work

Conclusions

• Initial thermal analysis is critical

• Project with high didactic potential

Future Work

• Fix the overheating issue

• Design other amplifier classes such as AB and B to be

able to compare its performance, efficiency and so

forth

5. Conclusions and Future Work

46

Thanks!

Any Question?