TRF1020 GSM Receiver EVM

Application BriefSWRA018

Digital Signal Processing Solutions 09/22/98

TRF1020 GSM Receiver EVMWireless Communication Business Unit

This document describes the Texas Instruments (TI™) TRF1020 evaluation module(EVM) board and associated EVM software, which allows the evaluation and thedemonstration of the TRF1020 GSM Receiver.

Contents

Product Support ............................................................................................................................................ 3The TI Advantage Extends Beyond RF to Every Other Major Wireless System Block......................... 3

Introduction ................................................................................................................................................... 4Functional Description.................................................................................................................................. 5Low Noise Amplifier ...................................................................................................................................... 5RF Mixer ......................................................................................................................................................... 6First IF Amplifier and IF Mixer ...................................................................................................................... 6

I/Q VCO........................................................................................................................................................... 6Second IF Amplifier and I/Q Mixer ............................................................................................................... 6Serial Control Interface ................................................................................................................................. 6

Table Formats and Styles .................................................................................................................... 7

TRF1020 Schematic....................................................................................................................................... 8Parts List ........................................................................................................................................................ 9PCB Layout .................................................................................................................................................. 11EVM Design Notes....................................................................................................................................... 11

Tank Circuit........................................................................................................................................ 11

Impedance Matching ................................................................................................................................... 13Low Noise Amplifier and SAW Filter Matching................................................................................... 13Mixer 1 Output and IF Amplifier 1 Input Matching .............................................................................. 14

Mixer2 Output Matching.............................................................................................................................. 15IF2 Amplifier/Demodulator Input Matching ............................................................................................... 15

LO1 Buffered Outputs ........................................................................................................................ 15

EVM Tests .................................................................................................................................................... 16Typical Test Setup ............................................................................................................................. 16Test Conditions .................................................................................................................................. 16

Typical Performance ................................................................................................................................... 18Test Data ........................................................................................................................................... 18

EVM Software .............................................................................................................................................. 24

Evaluation Board Disclaimer...................................................................................................................... 24

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2 TRF1020 GSM Receiver EVM

FiguresFigure 1. TRF1020 Functional Block Diagram....................................................................................... 5Figure 2. TRF1020 Schematic ................................................................................................................. 8Figure 3. PCB Layout............................................................................................................................. 11Figure 4. Varactor Controlled LC Tank Circuit .................................................................................... 12Figure 5. LNA Input/Output &SAW Filter Match .................................................................................. 13

TablesTable 1. Control Word Bit Assignment................................................................................................. 7Table 2. Parts List................................................................................................................................... 9Table 3. Evaluation Board Component Summary.............................................................................. 10Table 4. First IF Amplifier Gain Control (see Note 1)......................................................................... 17Table 5. Second IF Amplifier Gain Control......................................................................................... 17


TRF1020 GSM Receiver EVM 3

Product Support

The TI Advantage Extends Beyond RF to Every Other Major WirelessSystem Block

RFInterface

RFInterfaceAudio

InterfaceAudio

Interface TMS320C54X

DSP Core

S/W

TMS320C54X

DSP Core

S/W

ARM7TDMIE

(C470)Microcontroller

S/W

ARM7TDMIE

(C470)Microcontroller

S/W

SpeakerSpeaker MicrophoneMicrophone

User DisplayUser Display

KeyboardKeyboard

SIM CardSIM Card

Op AmpsOp Amps

SwitchesSwitches

RegulatorsRegulators

S IN G L E C H IP D IG IT A L B A S E B A N D P O W E R M G M T

S IN G L E C H IP A N A L O GB A S E B A N D

TS

C60

00A

SIC

BA

CK

PL

AN

E

Power AmpTRF7xxx, TRF8xxx

Power AmpTRF7xxx, TRF8xxx

ReceiverTRF1xxx

ReceiverTRF1xxx

SynthesizerTRF2xxx

SynthesizerTRF2xxx

ModulatorTRF3xxx

ModulatorTRF3xxx

R F S E C T IO N

Digital Baseband

TI’s single-chip Digital Baseband Platform combines two high-performance core processors – a digital signalprocessor tailored for digital wireless applications and a microcontroller designed specifically for low-powerembedded systems. The customizable platform helps wireless digital telephone manufacturers lowercomponent counts, save board space, reduce power consumption, introduce new features, savedevelopment costs and achieve faster time to market, at the same time giving them flexibility andperformance to support any standard worldwide.

Analog Baseband

TI analog baseband components provide a Mixed-signal bridge between the real world of analog signals anddigital signal processors, the key enabling technology of the digital wireless industry. Using a seamlessarchitecture for wireless communications technology, TI matches its baseband interfaces, radio frequencyICs and power management ICs to digital signal processing engines to create complete DSP Solutions fordigital wireless systems.

Power Management

TI provides power management solutions with integration levels designed to meet the needs of a range ofwireless applications. From discrete LDOs and voltage supervisors to complete power supplies for thebaseband section, TI power management solutions play an important role in increasing wireless battery life,time-to-market and system functionality.

For more information visit the Wireless Communications web site at www.ti.com/sc/docs/wireless/home.htm.

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GSM RF System Block Diagram

1/M1 1/N1

Ref Divider

PhaseComp 1

PhaseComp 2

PhaseComp 3

1/M2 1/N2

1/M3 1/N3

.Cntrl Pwr Intfc Dwn

Ref OscDuplexer

PA

ANT

880-915MHz

FreqCont

Level Cntrl

Rx/Tx LO1074-1109

MHz

0

90

I out

Q out

TANK

RF BPF

1st LO

VCO

LNA

1st MIXER

149 MHz

925-960MHz

IFAmp

Serial IFPwr Dwn&AGC

IF BPF LPF

52 MHz

2nd MIXER

IFAmp

2 22 2

2

2

SSM

PADriver

Q in

I in

0

90TANK

194MHz

FILTER Pwr DwnSerial IF

LP Filt Limiter

div by 2

BPF

VCO

97 MHz to2nd LO

Div by 4

TRF 1020 Receiver

TRF3520 ModulatorTRF2020 Synthesizer

VCO out

TRF7610

The TRF1020 is used in conjunction with the TRF3520 Modulator, the TRF2020Synthesizer, and the TRF7610 Power Amplifier to create a complete GSM solution.

IntroductionThe TRF1020 evaluation board is comprised of a multi-layer printed circuit board andrequired components. The following information is included to aid in the assessment ofthis device:

q Block Diagram and Functional Description

q Schematic

q Parts List

q PCB Layout

q EVM Design notes

q Impedance Matching

q EVM Tests

q Typical Performance

q EVM Software



Figure 1. TRF1020 Functional Block Diagram

Mix2_IF-

Mix2_IF+

43

44

34

35

2nd IFAmplifier

BufferIF Mixer

2nd LO FromModulator

( Mix2_LO )

IF2_IN+

IF2_IN-

Mix1_IF-

Mix1_IF+

20

21

31

30

1st IFAmplifier

BufferRF Mixer

IF1_IN+

IF1_IN-

ExternalSAWFilter

LNA

LNA_OUTLNA_IN

MIX1_RF

Buffer

Div by 4 VCOExternal

Tank

OS2_BASE

OS2_EMIT

41

39

SYNTHLoop Filter

IQMAX_Q+

IQMAX_Q-

1st LO in( OS1_EMIT )

To SYNTH( OS1_SYN )

To TransmitModulator( OS1_MOD )

28

29

24

5

4

19

14 16

To SYNTH( OS2_SYN)

38

BUFFER

BUFFER

BUFFER

BUFFER

BUFFER

BUFFER 1

2

48

IQMX_I+

IQMX_I-

Divide-by-fourTo SYNTH

( OS2_DIV4)

0 deg

90 deg

I/Q Mixer

36

ExternalSAWFilter

LowPassFilter

Serial Interface

Dig

_V

cc

Dig

_C

MP

CL

K

Str

ob

e

DA

T

Dig

_G

ND

7 8 9 10 11

7

12

Functional DescriptionThe TRF1020 is a single-chip Radio Frequency (RF) receiver suitable for 900 MHzwireless Global Systems for Mobile communications (GSM) applications. It combines aLow Noise Amplifier, an RF Mixer, an IF Mixer, two IF AGC Amplifiers, an I/Q Mixer and abuffered VCO into one small package. These functions are described in the followingsections. Ample terminals have been reserved to provide for a high degree of signalgrounding and to minimize cross talk.

Low Noise AmplifierThe low noise amplifier (LNA) receives the Gaussian-filtered minimum shift keying(GMSK) modulated carrier signal and boosts the level. Nominal gain of the LNA is 12.4dB with a Noise Figure of 2.1 dB. The LNA is also capable of switching from +12.4 dBgain state to a -5.8 dB attenuation state. Control of this switching is accomplished usingthe LNA Gain Control (LNAP) bit of the serial control word. When true, the bias of theLNA to the high gain state is enabled and when false, the amplifier is unbiased.Attenuation is achieved by the off-state isolation of the structure.

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RF MixerThe RF mixer utilizes an external oscillator to translate the receive frequency signal to thefirst intermediate frequency (IF). The mixer’s output is differential open-collector. Thisenables relatively simple matching to an external high impedance SAW filter. TheApplications Evaluation Board uses high side frequency injection for a first intermediatefrequency (IF) frequency of 149 MHz.

First IF Amplifier and IF MixerThe second downconverter group consists of the first IF amplifier whose output feeds theIF mixer. Because the first IF amplifier output is not brought out to the device terminals,the two functions are specified together.

In order to provide for cascaded operation of the first and second IF amplifiers, it ispossible to bypass the IF mixer function. Mixer bypassing is accomplished by using theMX2BYP bit (1 = mixer bypassed, 0 = normal operation).

The gain for this stage is variable from 0 to 42 dB and is selected by command of theserial control word bits D06 to D11. After amplification, the signal is down converted to52 MHz using an external local oscillator (LO) frequency of 97 MHz.

I/Q VCOThe I/Q VCO generates a tone in the 208 MHz range which can be controlled by thevoltage applied to the varactor diode on the external tank circuit. A buffered sample ofthe oscillator output is provided at the OSC2_SYN terminal. The 208 MHz signal isconverted to 52 MHz using an on-chip divide-by-4 network then routed to the I/Q Mixer.The divide-by-4 signal is also available through a buffer amplifier at the OSC2_DIV4terminal.

Second IF Amplifier and I/Q MixerThis block provides an additional 42 dB of gain, then down converts the 2nd IF signal tobaseband utilizing the on-chip Voltage Controlled Oscillator (I/Q VCO). Gain is variablefrom 0 to 42 dB and is controlled by the serial word bits D14 through D19. Differentialoutputs are provided for both the I and Q signals.

Serial Control Interface All TRF1020 functional blocks can be individually powered up or down via the serialinterface.

The TRF1020 device register is manipulated via a synchronous serial data port. TheSerial Control Interface provides power up / power down capability for each one of thefunctional blocks. One 24 bit word is clocked into a temporary holding register with theleast significant bit clocked first. The operation register is loaded with the new dataresiding in the temporary registers using the rising edge of the STROBE input.

Table 1 lists the format of the control word.



Table Formats and Styles

Table 1. Control Word Bit Assignment

Bit FUNCTION Signal Name

D0 LNA power control LNAP

D1 LNA gain control LNAG

D2 RF mixer standby MX1STBY

D3 RF mixer power MX1P

D4 IF mixer power MX2P

D5 IF mixer bypass MIX2BYP

D6 IF amp 1, gain control bit 1 IF1AGC1






D12 Demod power control DMODP

D13 Demod standby DMODSTBY







D20 Demod DC correction DMDISABLE

D21 <not used> <not used>



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TRF1020 Schematic

Figure 2. TRF1020 Schematic

A

82pF

C77

J15

3

56pF

C53

390n

HL1

6

IF2

_IN

R42

47K

9pF

C84

C85

0.01

uF

3 1

CR

1M

MB

V21

09

1 2

J21

39nH

L17

J11

120n

H

L19

C3

100p

FC

835p

FC

8622

pF

DE

M_

LO

R50

0

VC

CR

510

L3 180n

H

100p

FC

1

12pF

C82

1000

pF

C74

1000

pF

C76

1000

pF

C75

5.1K

R30

VC

C

2 134 5

T2

617P

T-10

26

+12V

1 2

1 2

C14

1uF

1uF

C16

W

CW

CC

W

10K

R36

-12V

+12V

-12V

6

1

3+

7

+1

2V

2- 5

4

-12

VU

2M

C3

40

71

D

C51

0.1u

FJ1

2

R16

10K

-12V

+12V

56pF

C26

10K

R3

I_O

UT

410

K

R15

AM

PLI

TUD

E B

ALA

NC

E

-12V

OFF

SE

T A

DJU

ST

W

CW

CC

WR

12

10K

R13

10K9.

1K

R14

100p

FC

45

100p

FC

4610

KR

29

W

CW

CC

W

2K

R26

AM

PLI

TUD

E B

ALA

NC

E

R21

22K

R18

22K

W

CW

CC

W

2K

R17

OFF

SE

T A

DJU

ST

10K

R23R

2210

K

9.1K

R24

-12V

W

CW

CC

WR

19

10K

6

1

3+

7

+1

2V

2- 5

4-12

VU

3M

C3

40

71

D

J10

100p

FC

20.

01uF

C49

C47

100p

F

OS

2_

/4

VC

C

7

8

9

10

6

1

2

3

4

5

11

12

36

35

34

33

32

30

29

28

27

26

25

31

20 19 18 17 16 15 14 13484746454443424140393837

21222324

TRF1

020

U10

5.6p

F

C87

39pF

C15

470n

H

L2

5pF

C81

C80

12pF

VC

C

C20

5pF

C32

100p

FL7 6.

8nH

1P

1:A

6.8n

H

L22L5 15

nH

2pF

C37

VC

C 100p

FC

34

4pF

C25

2.7p

F

C28

RF

_IN

L6 15nH 7

P1:

G

2P

1:B

R4

1.5K

10pF

C41 1KR

6

1KR5

J8

-12V

56pF

C19

10K

R20

R25

10K

C50

0.1u

FJ1

3

6P

1:F

9P

1:I

5P

1:E

4P

1:D

+12V

Q_

OU

T

1KR10

8P

1:H

10pF

C44

1.5K

R11

R7

1.5K

1.5K

R9

10pF

C431KR

83

P1:

C

10pF

C42

DR

AW

NC

ST

OV

ALL

AP

PR

OV

ALS

ISS

UE

D

CH

EC

KE

D

J B

RID

GE

S

BC

D

L15

390n

H

J14

33pF

C73

MIX

2_

OU

T

1

A

2 134 5

T1

617P

T-10

26

0R1 0R2

1000

pFC

72 VC

C 0.01

uFC

52

C5

9pF

VC

O2

_B

UF

VC

CW

CW

CC

WR

44

10K

0R43

2

J1

C58

3.3p

F

J2

200

R39

56nH

L12

C6

100p

F

MIX

2_

LO

390n

HL1

8

C7

0.01

uF

VC

C56

pFC

11

C10

56pF

C21

5pF

VC

C

L1 150n

H

100p

FC

4

L11

150n

H

L9

120n

H

C29

100p

F

C

VC

C

BD

J40R33

MIX

1_

OU

T

VC

C

1000

pF

C23

C24

100p

F

R40 50

1000

pFC

55

C54

1pF

OS

I_S

YN

L8

120n

H

L23

180n

H

L13

3.9n

H

C31

330p

F

L10

180n

H1

2IN

5O

UT

32

14

89

10

7

11

IN6

OU

T

SF

10

76

AS

F1

3.9n

H

L14

C38

33pF

330p

F

C22

47nH

L265 4

1 3

T3

ETC

1-1-

13 47nH

L25

VC

C

OS

I_M

OD

1pF

C5750R41

J6M

IX1

_L

O

1

F

1 345

ETC

1-1-

13

T4

E

J50R32

IF1

_IN

C48 22

0pF

C59

18pF

C56

39pF

39nH

L27

C35 22

0pF

150n

H

L28

-OR

- M

UR

ATA

39nH

L21

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120n

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L29

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Sep

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FC

276.

8nH

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R31

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C64

100p

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0

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OF

RE

V.

C

1



Parts List

Table 2. Parts List

Ref. Designator Value Description QTY Part Number Manufacturer

C1,2,3,4,6,24,27,29,32,34,45,46,47,60, 64

100pF Capacitor 15 GRM36COG Series Murata

C5, 84 9 pF Capacitor 2 GRM36COG Series Murata

C7,49,52,61,85 0.01 µF Capacitor 5 GRM36COG Series Murata

C10,11,19,26,53 56 pF Capacitor 5 GRM36COG Series Murata

C14,16,62 1 µF Capacitor 3 TA025TCM105KAR Venkel

C15 39 pF Capacitor 1 GRM36COG Series Murata

C56 39 pF Capacitor 1 GRM42-6COG Series Murata

C20, 21, 81, 83 5 pF Capacitor 4 GRM36COG Series Murata

C22,31 330 pF Capacitor 2 GRM42-6COG Series Murata

C23, 55, 72, 74, 75, 76 1000 pF Capacitor 6 GRM36COG Series Murata


C28 2.7 pF Capacitor 1 GRM36COG Series Murata




C41,42,43,44 10 pF Capacitor 4 GRM36COG Series Murata

C50,51 0.1 µF Capacitor 2 GRM36COG Series Murata



C59 18 pF Capacitor 1 GRM42-6 Series Murata

C63 1 µF Capacitor 1 GRM42-6Y5V Series Murata



C80, C82 12 pF Capacitor 2 GRM36COG Series Murata



L1,11 150 nH Inductor 2 1008CS Series Coilcraft

L2 470 nH Inductor 1 LL2012-FR47K Toko

L3,10, 23 180 nH Inductor 3 805HS Series Coilcraft

L4, 7 6.8 nH Inductor 2 603HS Series Coilcraft

L5, 6 15 nH Inductor 2 603HS Series Coilcraft

L8, 9, 29 120 nH Inductor 3 603HS Series Coilcraft

L12 56 nH Inductor 1 603HS Series Coilcraft

L13, 14 3.9 nH Inductor 2 603HS Series Coilcraft

L15, 16, 18 390 nH Inductor 3 1008CS Series Coilcraft




L22 6.8 nH Inductor 1 LL1005 Series Toko

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R1, 2, 31, 32, 33, 43,50, 51

0 Ω Resistor 8 ERJ-2GEJ0R00 Panasonic

R3, 13, 15, 16, 20, 22,23, 25, 29

10 KΩ Resistor 9 ERJ-2GEJ103 Panasonic

R4, 7, 9, 11 1.5K Ω Resistor 4 ERJ-2GEJ152 Panasonic

R5, 6, 8, 10 1K Ω Resistor 4 ERJ-2GEJ102 Panasonic

R14, 24 9.1K Ω Resistor 2 ERJ-2GEJ912 Panasonic

R18, 21 22K Ω Resistor 2 ERJ-2GEJ223 Panasonic

R30 5.1K Ω Resistor 1 ERJ-2GEJ512 Panasonic

R39 200 Ω Resistor 1 ERJ-2GEJ201 Panasonic

R40, 41 50 Ω Resistor 2 ERJ-2GEJ500 Panasonic

R42 47K Ω Resistor 1 ERJ-2GEJ473 Panasonic

R12, 19, 36 10K Ω Adjustable Resistor 3 3214W-103 Bourns

R17, 26 2K Ω Adjustable Resistor 2 3214W-202 Bourns

R44 10K Ω Adjustable Resistor 1 3296-Y-1-103 Bourns

P1 Serial 9-Pin Connector 1 745990-4 Amp

J1,2,4,5,6,8,10,11,12,13,14,15

SMA Connector 12 142-0701-801 EF Johnson

J20,21 DC Voltage Connector 2 4-103239-0 Amp

U1 Voltage Regulator 1 TK11230 Toko

U10 GSM Receiver 1 TRF1020 T. I.

U11, 12 Operational Amplifiers 2 MC34071D Motorola

CR1 Varactor Diode 1 MMBV2109 Motorola

F1 Differential SAW Filter 1 RFM_SF 1076A RF Monolithics

F2 Image Reject SAW Filter 1 SAFC942.5MA70N Murata

T1, 2 Balun Transformer 9:1 2 617PT-1026 Toko

T3,4 Balun Transformer 1:1 2 ECT1-1-13 MA/COM

Table 3. Evaluation Board Component Summary

Description Quantity Required

Capacitors 68

Inductors 27

Resistors 34

Potentiometers 6 Semiconductors 5 Balun Transformers 4 SAW Filters 2

NOTE: Many of the components used are to aid in taking measurements and injecting signals ina 50 Ohm environment. In actual use, the component count could be greatly reduced.



PCB Layout The EVM board is comprised of a multi-layer printed circuit board, a TRF1020 device,SMA connectors, and the necessary peripheral discrete components.

Figure 3. PCB Layout

EVM Design Notes

Tank Circuit

The VCO generates a signal in the 208MHz range that is used in the downconversion ofthe IF2 signal to baseband. The 208 MHz signal is later translated to 52MHz through theon-chip divide-by-four circuit.

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Figure 4. Varactor Controlled LC Tank Circuit

R42=47K

1

2

J21

CR1MMBV2109

C84=9pF

L17=39nH

C82=12 pF

C81=5pF

C80=12pF

Terminal 39OS2_Emit

Terminal 40OS2_Gnd

Terminal 41OS2_Base

TRF1020Vtune

NOTE: The tank circuit in Figure 2 has been redrawn in Figure 4 for clarification.

The tank resonant frequency is defined by the following formula:

fresonance L Ceq

=1

217

π

where

CeqC C C CCR

= +

+ +

− −1 1 1 1

84 1

1

80 82

1

, CCR1 = Varactor’s capacitance

On the EVM board, the VCO was designed to operate at 208 MHz. The calculatedresonance frequency is as follows:

CR1 = 50 pF (at 1.5V, measured on the EVM board)

CeqpF pF pF pF

pF= +

+ +

=

− −1

9

1

50

1

12

1

1213 627

1 1

. ,

with L17= 39nH

fL Ceq

MHzresonance = =1

2218 32

17π.

The difference in frequency between the calculated and measured resonant frequenciesis attributed to the actual varactor capacitance, component tolerances, board layout, andthe interaction of the TRF1020 with C81. C81 is primarily used to adjust the outputpower of the oscillator by controlling the feedback current of the internal transistor, but itwill have some small effect on the actual resonant frequency.



The oscillator frequency tuning range is approximately 6 MHz. The tuning range iscontrolled by the varactor changing in capacitance when the tuning voltage, (Vtune) isadjusted from 0V to 3.0 V. Vtune is adjusted from 0 to 3Vdc using R44 or can be appliedexternally at J24 if R43 is removed.

The use of high Q components in the tank circuit is required as they affect the impedanceseen by the TRF1020. The Q’s of the inductor (L17), the capacitors, and varactors arevery critical, as the selection of these components affects the attenuation that the tankcircuit will provide. An increase in attenuation reduces the tank resonant signal leveland, if not designed properly, can degrade the oscillator start up properties. See theTRF3520 GSM RF Modulator/Driver Amplifier EVM Application Brief, (TI LiteratureNumber SWRA020), for a detailed description of Q and how it can affect oscillatorcircuits.

Impedance Matching

Low Noise Amplifier and SAW Filter Matching

The diagram below shows the matching circuitry used on the TRF1020 LNA input andimage-reject SAW filter. The LNA input impedance matching network primarilydetermines the gain, noise figure and input return loss performance. A series-C (C32),shunt-L (L7), series-C (C20) matching network is used to obtain optimum noise figureperformance. The trade-off for this optimization is degraded input return loss and lowergain. Components L6 and C27 provide a matching network between the LNA output andSAW Filter input. The output of the SAW Filter is matched to the input of Mixer1 withanother series-C (C66), shunt-L (L4), series-C (C25) circuit. The two series capacitors,(C66 and C25) are critical to the cascaded input 3rd-order intercept point performance.The circuitry depicted is a compromise between the best gain, noise figure, input returnloss, and input 3rd-order intercept point.

Figure 5. LNA Input/Output &SAW Filter Match

SawFilter

Vcc

C27=100pF C66=6pF

L4=6.8nH

C25=4pF

LNA

C32=100pF C20=5pF

L7=6.8nH

L6=15 nH

Terminal 14

Terminal 16

RF In J8

Terminal 19

Mix1 In

SWRA018


Mixer 1 Output and IF Amplifier 1 Input Matching

The output of Mixer 1 is differential and has a real impedance component of 2000 Ohms.This impedance is transformed from 2000 Ohms to 50 Ohms at capacitors C22/C31using components L8, L9, C21, L10, and L23. The value of C21 is critical for both noisefigure and input 3rd -order intercept point. Depending on the placement of C22 and C31,the signal can either continue through the SAW filter or brought out to measurement pointJ4 (Mix1 Output), using a 1:1 balun transformer, (T3).

Figure 6. Mix1 Output to IF Amp1 Input Match

RFMSF1076A

FromTerminal 31

FromTerminal 30

Vcc

L9=120nH

L8=120nH

C29=100pF

C21=5pF C38=33pF

L10=180nH

L23=180nH C22=330pF

C31=330pF

L26=47pF

L25=47pF

L27=39nH

L21=39nH

C56=39pF C59=18pF

L28=150nH

L29=120H

C28=2.7pF

L22=6.8nH

To Terminal21

To Terminal20

C35=220pF

C48=220pF

Mix1Output

IF Amp 1Input

ETC1-1-13

T3 T4J4

ETC1-1-13

J5

Mix1 OutputIF Amp 1

Input

The SAW filter provides 149 MHz filtering and has an input impedance of approximately850 Ohms. Starting at capacitors C22 and C31, the impedance is transformed from 50Ohms to 850 Ohms using components C38, L25, and L26. After the filter, the impedanceis transformed back from 850 Ohms to 50 Ohms at capacitors C35 and C48 usingcomponents C56, L21 and L27. Depending on the placement of C35 and C48, the signalcan either continue on to the input of IF Amplifier1 or brought out to connection point J5(IF1_In), using a 1:1 balun transformer, (T4).

With the signal path connected to J5, the IF Amplifier1 can be driven externally. Thisallows for individual testing of IF Amp1/Mixer2. When cascaded together, Mix1 output,the differential SAW filter, and IF Amp1 input are very sensitive. Small changes in thevalues of components C21 and C59 will greatly affect the path’s gain, noise figure, andinput 3rd order intercept point.

Finally, components L22 and C28 are used to create a resonant trap circuit for the Mix1LO signal, (Frequency Range 1079-1109), which can couple into the receiver at this pointand interfere with proper performance. Again, the tuning utilized is a compromisebetween the best gain, noise figure, and input 3rd-order intercept point.

NOTE: Much of the impedance matching shown in Figure 6 was to aid in takingmeasurements and injecting signals in a 50 Ohm environment. In actual use, thecascaded matching circuitry could be greatly simplified.



Mixer2 Output Matching

Figure 7. Mixer2 Output

J14C73=33pF

L15=390nH

617PT-1026

T14

5 1

2

3L1=150nH

L11=150nH

FromTerminal 35

FromTerminal 34

Vcc

C7=.01uF

C11=56pF

C10=56pF

C72=1000pF Mix2 Out

9:1 Transformer

Mix2_Out

Mixer 2 translates the 149 MHz signal to a 2nd IF frequency of 52 MHz. Components L1,L11, C10, and C11 create a resonant circuit at approximately 52 MHz. Mixer2 wasspecified to have a load impedance of 2500 Ohms. The 9:1 balun transformer, (3:1turns ratio) together with L15 and C73 provide a load impedance of 2500 Ohms to theMixer2 output while presenting a 50 Ohm impedance to the test environment atconnector J14. In particular, the 9:1 balun transforms the 2500 Ohm impedance toapproximately 277 Ohms. Finally, L15 and C73 were adjusted to obtain the best gainand complete the impedance transformation to 50 Ohms.

IF2 Amplifier/Demodulator Input Matching

Figure 8. IF2 Amplifier/Demodulator Input

The IF2 Amplifier/Demodulator has a specified input impedance of 2500 Ohms. C53,C77 and L16, combined with the 9:1 balun transformer present a 50 Ohm impedance tothe test environment at connector J15 and provide a load impedance of 2500 Ohms tothe input of the IF2 Amplifier/Demodulator. L3 and C15 form a resonant tank atapproximately 52 MHz. L2 and C87 are used to create a 97 MHz trap, (care should betaken as the 97 MHz trap will affect the 52 MHz tank circuit). This trap is necessary toattenuate the Mix2 LO which can couple into the circuit at this point.

LO1 Buffered Outputs

Os1_ Mod and Os1_Syn, (TRF1020 terminals 28 and 29) are the two available bufferedoutputs for the 1st local oscillator input, (LO1). These outputs are not brought out to testpoints on the TRF1020 EVM. Components L14, R41, C57, L13, R40, and C54 representtypical tuning elements if the outputs are to be used.

IF2_IN

J15C77=82pF

C53=56pF L16=390nH

617PT-1026

T24

5 1

2

3

C74=1000pF

C76=1000pF

C75=1000pF

L3=180nH C15=39pF C87=5.6pF

L2=470nH

To Terminal 43

To Terminal 449:1 Transformer

IF2 In

SWRA018


EVM Tests

Typical Test Setup

Figure 9. Typical Test Setup for the TRF1020 EVM

Device UnderTest

RF Source

Mixer2 LOSource(LO2)

Mixer1 LOSource(LO1)

SpectrumAnalyzer

DC PowerSupply

J2

P1

J6

J4, J12, J13, or J14(Dependant on Test)

J5, J8, orJ15

(Dependanton Test)

Test Conditions

The tests are performed at room temperature.

q Vcc = +3.0

q RF Input = 940 MHz

q LO1=1098 MHz @ -5 dBm

q LO2=97 MHz @ -10 dBm

q I/Q VCO Frequency=208 MHz



Table 4. First IF Amplifier Gain Control (see Note 1)

IF1AGC6 IF1AGC5 IF1AGC4 IF1AGC3 IF1AGC2 IF1AGC1 GAIN (dB) 0 0 0 0 0 0 0 0 0 0 0 0 1 3.0 0 0 0 0 1 1 6.0 0 0 0 1 1 1 9.0 0 0 1 0 0 0 12.0 0 0 1 0 0 1 14.5 0 0 1 0 1 1 17.5 0 0 1 1 1 1 20.5 0 1 1 0 0 0 23.0 0 1 1 0 0 1 26.0 0 1 1 0 1 1 29.0 0 1 1 1 1 1 32.0 1 1 1 0 0 0 34.5 1 1 1 0 0 1 37.0 1 1 1 0 1 1 39.5 1 1 1 1 1 1 42.0

NOTE: See Table 1, Control Data BIT/Signal Name Map

Table 5. Second IF Amplifier Gain Control

IF2AGC6 IF2AGC5 IF2AGC4 IF2AGC3 IF2AGC2 IF2AGC1 GAIN (dB) 0 0 0 0 0 0 0 0 0 0 0 0 1 3.0 0 0 0 0 1 1 6.0 0 0 0 1 1 1 8.5 0 0 1 0 0 0 12.0 0 0 1 0 0 1 15.0 0 0 1 0 1 1 18.0 0 0 1 1 1 1 21.0 0 1 1 0 0 0 24.0 0 1 1 0 0 1 27.0 0 1 1 0 1 1 30.0 0 1 1 1 1 1 33.0 1 1 1 0 0 0 36.0 1 1 1 0 0 1 39.0 1 1 1 0 1 1 40.0 1 1 1 1 1 1 42.5

SWRA018


Typical Performance

Test Data

LNA/Mix1 (Cascaded Operation) RF = 940 MHz @ -50 dBm, LO1 = 1089MHz @ -5 dBm, IF1=149 MHz, (Measurements include filter loss)

TestNo

Parameter Conditions Typical Test Results Min Typ Max

Units

1 Gain

Max LNAGain

Min LNAGain

25

27

6.8

29 dB

dB

2 Noise Figure Max LNAGain

Min LNAGain

3.8

6.8

4.5 dB

dB

3 3rd-order InterceptPoint (200 kHz tone separation)

Max LNAGain

Min LNAGain

-9.0

9.0

dBm

dBm

NOTE: Input RF power level may need to be increased in order to measure 3rd-order Interceptpoint.

IF1/Mix 2 Input Frequency = 149 MHz @ -75 dBm, LO2 = 97 MHz @ -10dBm, IF2 = 52 MHz

TestNo


Units

4 Gain Delta Max Gain 39 42.5 46 dB

5 Gain Step Error See Table 2 + 1 dB

6 Noise Figure (SSB) 9.4 15 dB

7 Input 3rd-orderIntercept Point (200 kHz tone separation)

Max Gain

Min Gain

-52.5

-9.6

dBm

dBm

NOTE: Gain error relative to gain state in Table 2.



VCO

TestNo

Parameter Conditions Typical Test ResultsMin Typ Max

Units

8 Frequency Range 206-212

MHz

9 Output power -14.5 dBm

10 Phase Noise 200 kHzOffset

-120 dBc/Hz

NOTE: The EVM is configured to use the on-board Vcc and R44 for frequency tuning. To applyan external tuning voltage, R43 must be removed.

IF2/Demodulator Input Frequency = 52.1 MHz @ -75 dBm

TestNo


Units

11 Gain Delta Max IF Gain 37 42 47 dB

12 Gain Error See Table 3 + 1 dB

13 Amplitude Balance + .7 dB

14 Phase Balance + 1 deg

NOTE: Gain error relative to gain state in Table 3.

LNA/Mix2 (Cascaded Operation) RF = 940 MHz @ -85 dBm, LO1 = 1089 MHz @ -5dBm, LO2 = 97 MHz @ -10 dBm, (Measurements include filter losses)

TestNo


Units

15 Gain Max IF Gain 56 dB

16 Noise Figure IF1 Gain=42 dB

IF2 Gain=42 dB

4.8 dB

NOTE: For maximum IF Gain control range, C28 should be changed to 4 pF. C22, C31, C35,and C48 must be properly oriented for cascaded operation.

SWRA018


LNA/Demodulator (Cascaded Operation) RF = 940.1 MHz @ -108 dBm, LO1 = 1089MHz @ -5 dBm, LO2 = 97 MHz @ -10 dBm, VCO enabled (Measurementsinclude filter losses)

TestNo


Units

17 IF Amplifier GainControl Range

0 to 80 dB

18 Noise Figure IF1 Gain=42 dB

IF2 Gain=30 dB

5.5 dB

NOTE: For maximum IF Gain control range, C28 should be changed to 4 pF. C22, C31, C35,and C48 must be properly oriented for cascaded operation.



LNA to Mixer 1 Gain

• RF In = 940 MHz @ -50dBm• LO = 1089 MHz @ -5 dBm• Cable/Balun Transformer Loss = 1.7 dB• LNA/Mix1 Gain = |-50 - (-24.62)| +1.7 dB = 27.08 dB

SWRA018


LNA to Mixer 1 Input 3rd Order Intercept Point

• RF1 In = 940 MHz @ -45dBm, RF2 In = 940.20 MHz @ -45dBm• LO = 1089 MHz @ -5 dBm• Cable/Balun Transformer Loss = 1.7 dB• IIP3 = |(-74.8/2)| - 45 = -7.6 dBm NOTE: Input power was increased from the specified –50 dBm to –45 dBm in order to measurethe 3rd order product above the noise floor.



LNA to Mixer 2 Gain

• RF In = 940MHz @ -85dBm• LO1 = 1089 MHz @ -5 dBm• LO2 = 97 MHz @ -10 dBm• Cable/Balun Transformer Loss = 1.7 dB• LNA/Mix2 Gain = |-85 - (-29.93)| +1.7 dB = 56.8 dB

SWRA018


EVM Software Windows-based software is supplied with the evaluation board. The software is intendedfor use in a Windows environment, 3.11or later version, Windows 95 or Windows NT. Nospecial memory is required to use the software.

q TRF1020.EXE

The TRF1020.exe file may be copied to the system hard drive or may be executeddirectly from the disk provided. To execute the program from the provided disk, simplytype the following.

A:\TRF1020 ↵ (Enter)

The program executes from the TRF1020.EXE file.

Connect the interface cable to the computer LPT port, then connect the cable to theEVM. The EVM software allows you to select the correct LPT port. Port selection isfound under the Options menu.

The TRF1020 functional blocks can be activated or deactivated individually by selectingthe corresponding button on the EVM software display. Available selections are FirstMixer Power, First Mixer Standby, Second Mixer Power, Second Mixer Standby,DeModulator Power, DeModulator Standby, LNA Bias, IF1 Gain, and IF2 Gain. Toactivate or deactivate a block, simply click on the desired state with the mouse.

Once the functional blocks have been selected, select SEND with the mouse to enablethe selected device state. SEND can be found at the top/center of the EVM softwarewindow.

Evaluation Board DisclaimerPlease note that the enclosed evaluation boards are experimental Printed Circuit Boardsand are therefore only intended for device evaluation.

We would like to draw your attention to the fact that these boards have been processedthrough one or more of Texas Instruments’ external subcontractors which have not beenproduction qualified.

Device parameters measured, using these boards, are not representative of any finaldatasheet or of a final production version. Texas Instruments does not represent orguarantee that a final version will be made available after device evaluation.

THE EVALUATION BOARDS ARE SUPPLIED WITHOUT WARRANTY OF ANY KIND,EXPRESSED, IMPLIED OR STATUTORY, INCLUDING BUT NOT LIMITED TO, ANYIMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULARPURPOSE.

TEXAS INSTRUMENTS ACCEPTS NO LIABILITY WHATSOEVER ARISING AS ARESULT OF THE USE OF THESE BOARDS.



References

TRF1020 GSM Receiver, Literature number SLWS028

TRF3520 GSM RF Modulator/Driver Amplifier EVM, Literature number SLWA020

TRF2020 Frequency Synthesizer, Literature number SWRA012

TRF7610 Silicon Mosfet Power Amplifier IC for GSM, Liter

ature number SLW5059

European Telecom Standards Institute Specification, 05.05 Radio Transmission & Reception

European Telecom Standards Institute Specification, 11.10 Mobile Station ConformitySpecifications

Documents

TRF1020 GSM Receiver EVM