background image

P

0_low

P

0_high

P

IM3_low

P

IM3_low

P

IM2

f

-f

LO 2

f

-f

LO 1

f

LO

f

+(f -f )

LO

2 1

f

+f

LO

1

f

+f

LO

2

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EVM Test Procedure

3.2

Two-Tone OIP3 Test

The output third-order intercept point (OIP3) is a measure of the linearity performance of a nonlinear
device. It is measured by a two-tone test. The following exercise measures OIP3 following all listed steps
in

Section 3.1

.

1. Press Mode

More (1 of 2)

Multitone.

2. Highlight row 11 for frequency offset = 4.5 MHz, press Toggle State, and then press Apply Multitone

to turn on a 4.5-MHz tone. Now, two tones with equal amplitude and frequencies, f

1

= 4.5 and

f

2

= 5.5 MHz, are configured for E4438C.

3. Measure the RF power of both RF tones, P

0

, which must be between

1.8 dBm to

2.8 dBm.

4. Measure the power, P

IM3

, of the third-order intermodulation product associated with each RF tone. It is

approximately

66.5 dBm after the cable loss compensation.

5. OIP

3

can be calculated by the equation OIP

3

= P

0

+ (P

0

P

IM3

)/2. The worst OIP3 associated with

either the low- or the high-frequency tone is selected as the OIP3 of the modulator. The OIP3 at 1 GHz
is approximately

29.8 dBm

±

1 dBm. Caution must be taken for accurately measuring the small P

IM3

when the large P

0

is present. It is helpful to reduce the span and RBW settings of the spectrum

analyzer so that the IM3 component is at least 20 dB above the noise floor, as well as by increasing
the RF attenuator setting until P

IM3

is no longer varying with increased RF attenuation setting.

Figure 3. Two-Tone OIP3 Output Spectrum

5

SLWU073

October 2011

TRF3705EVM Evaluation Module

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Copyright

©

2011, Texas Instruments Incorporated

           

Summary of Contents for TRF3705

Page 1: ...he RF power amplifier Contents 1 Introduction 2 1 1 System Block Diagram 2 1 2 EVM Jumper Configuration 2 2 TRF3705 EVM Test Configuration 3 2 1 Test Block Diagram 3 2 2 Test Equipment 3 2 3 Calibrati...

Page 2: ...m Block Diagram 1 2 EVM Jumper Configuration Table 1 lists the locations of the installed jumpers in the default configuration of the evaluation module EVM Table 1 Default Jumper Connections Jumper De...

Page 3: ...quivalent Signal generator for LO input signal Agilent E4438C or equivalent Arbitrary waveform generator Agilent E4438C or equivalent Spectrum analyzer Agilent E4440A or equivalent 2 3 Calibration The...

Page 4: ...re configured for E4438C Press Multitone Off On until On is highlighted to generate the multitone waveform Connect I signals to J4 I and J3 I and the Q signals to J5 Q and J6 Q Adjust the differential...

Page 5: ...m 4 Measure the power PIM3 of the third order intermodulation product associated with each RF tone It is approximately 66 5 dBm after the cable loss compensation 5 OIP3 can be calculated by the equati...

Page 6: ...duct This notice contains important safety information about temperatures and voltages For additional information on TI s environmental and or safety programs please contact the TI application enginee...

Page 7: ...ncy energy and has not been tested for compliance with the limits of computing devices pursuant to part 15 of FCC or ICES 003 rules which are designed to provide reasonable protection against radio fr...

Page 8: ...na type and its gain should be so chosen that the equivalent isotropically radiated power e i r p is not more than that necessary for successful communication This radio transmitter has been approved...

Page 9: ...roduct only after you obtained the license of Test Radio Station as provided in Radio Law of Japan with respect to this product or 3 Use of this product only after you obtained the Technical Regulatio...

Page 10: ...property damage personal injury or death If there are questions concerning these ratings please contact a TI field representative prior to connecting interface electronics including input power and in...

Page 11: ...egulatory and safety related requirements concerning its products and any use of TI components in its applications notwithstanding any applications related information or support that may be provided...

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