NATIONAL INSTRUMENTS PXI-5650 Analog Signal Generator Installation Guide

NI-RFSG driver containing the entire NI-RFSG API, including calibration functions.
Folder containing NI-RFSG calibration API VIs. You can access calibration functions from the NI-RFSG calibration section of the LabVIEW function palette.

Documentation Requirements

You might find the following documentation helpful as you write the calibration procedure: · NI PXIe-5673 Specifications · NI PXIe-5673E Specifications · NI PXIe-5673 Calibration Procedure · NI PXIe-5673E Calibration Procedure · NI 5450 Calibration Procedure · NI PXI-5650/5651/5652 Calibration Procedure · NI PXIe-5650/5651/5652 Calibration Procedure · NI RF Signal Generators Getting Started Guide · NI RF Signal Generators Help, including LabVIEW VI programming
references
These documents are installed with NI-RFSG. You can also download the latest versions of documentation at ni.com/manuals.
This calibration procedure calibrates the NI PXIe-5611 I/Q modulator as a stand-alone device. To calibrate the NI PXIe-5673 or NI PXIe-5673E, refer to their calibration procedures at ni.com/manuals.

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NI PXIe-5611 Calibration Procedure

Password
The default password for password-protected operations is NI.
Calibration Interval
The measurement accuracy requirements of your application determine how often you should calibrate your device. NI recommends that you perform a complete calibration for the NI 5611 at least once a year. You can shorten this calibration interval based on the accuracy demands of your application.
Calibration Overview
Calibration involves verification, and, if necessary, adjustment, and reverification of the NI 5611.
Verification is the process of testing to ensure that the accuracy of the device. Perform verification post-adjustment to determine if the adjustment was successful.
Adjustment is the process of measuring and compensating for device performance to improve the measurement accuracy. Performing an adjustment updates the calibration date.
Perform a complete calibration to guarantee successful adjustment and performance of the NI 5611 for a one-year calibration interval. After adjustment, repeat verification to ensure that the device meets the calibration test limits.
After calibrating the NI 5611 as a stand-alone device, NI strongly recommends that you calibrate the NI 5673, which includes the NI 5611. To calibrate the NI PXIe-5673 or NI PXIe-5673E, refer to their calibration procedures at ni.com/manuals.

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Figure 1 shows the programming flow for a complete calibration.

Verify
Adjust (Calibration Dates and Temperatures Updated)
Verify

Document Pre-Adjustment
Results
Document Post-Adjustment
Results

Yes

Meets

No

Test Limits?

Calibration/ Verification Complete

Review Verification/ Adjustment Procedure
or Return Device

Figure 1. Complete Calibration Programming Flow

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NI PXIe-5611 Calibration Procedure

Test Equipment

Table 2 lists the equipment required to calibrate the NI 5611. If you do not have the recommended equipment, select a substitute calibration standard using the specifications listed in Table 2.

Table 2. Required Equipment Specifications for NI 5611 Calibration

Required Equipment Spectrum analyzer
Power meter
Power splitter
NI PXIe-5450 arbitrary waveform generator NI PXI-5652 RF signal generator 6 dB attenuator
50 terminator (included in the NI 5673 kit) Adapter SMA(m)-to-N(f) SMA torque wrench NI PXIe-5673 Cable Accessory Kit

Recommended Equipment

Specifications

Rohde & Schwarz (R&S) FSU Spectrum Analyzer with high-frequency preamplifier option (B23)

Frequency range: 50 MHz to 6.6 GHz Noise floor: <­152 dBm/Hz to 6.6 GHz

Anritsu ML2438A and a MA2472 diode sensor

Range: ­50 dBm to +10 dBm Frequency range: 50 MHz to 6.6 GHz Accuracy: 0.5%

Aeroflex/Weinschel 1593 SWR: 1.25 Amplitude tracking: <0.25 dB

NI PXIe-5450

This device must be fully calibrated before calibrating the NI 5611.

NI PXI-5652 Anritsu 41KB-6 NI 778353-01

This device must be fully calibrated before calibrating the NI 5611.
Frequency range: DC to 12 GHz SWR: 1.1
—

S.M. Electronics SM4241 VSWR: 1.15 : 1

NI 187106-01 NI 780567-01

1 N · m
Matched-length I/Q semi rigid SMA cable (4) LO semi-rigid SMA cable (1) RF flexible SMA cable (1)

SMA adapter plug/plug

Huber+Suhner

VSWR: 1.05 : 1

32_N-SMA-50-1/11-_NE

BNC (m) to BNC

—

—

(m) cable (36 inches)

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Test Conditions
Follow these guidelines to optimize the connections and the environment during calibration:
· Verify that the NI 5611, NI 5450, and NI 5652 are properly connected as indicated in Chapter 5, NI 5673 RF Vector Signal Generator or Chapter 6, NI 5673E RF Vector Signal Generator in the NI RF Signal Generators Getting Started Guide.
· Verification limits are defined assuming the same NI 5611, NI 5450, and NI 5652 is used during adjustment and verification.
· Keep cabling as short as possible. Long cables act as antennae, picking up extra noise that can affect measurements.
· Verify that all connections, including front panel connections and screws, are secure.
· Ensure that the PXI Express chassis fan speed is set to HI, the fan filters are clean, and the empty slots contain filler panels. For more information, refer to the Maintain Forced-Air Cooling Note to Users document available at ni.com/manuals.
· Keep relative humidity between 10% and 90%, noncondensing.
· Maintain an ambient temperature of 23 °C ±5 °C.
· Allow a warm-up time of at least 30 minutes after the chassis is powered on. The warm-up time ensures that the NI 5611 is at a stable operating temperature.
· Perform a self-calibration on the NI PXIe-5450 signal generator.
· Each verification procedure requires a delay to be inserted in between configuring all devices and acquiring the measurement. This delay may need to be adjusted depending on the instruments used but should always be at least 1,000 ms for the first iteration, 1,000 ms when the power level changes, and 100 ms for each other iteration.
Calibration Procedures
The calibration process includes the following steps:
1. Initial Setup–Install the device and configure it in Measurement & Automation Explorer (MAX). Refer to Chapter 5, NI 5673 RF Vector Signal Generator or Chapter 6, NI 5673E RF Vector Signal Generator in the NI RF Signal Generators Getting Started Guide for more information about how to configure your device.
2. Verification–Verify the existing operation of the device. This step confirms whether the device is operating within its specified range prior to adjustment.

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NI PXIe-5611 Calibration Procedure

3. Adjustment–Perform an external adjustment of the device that adjusts the calibration constants of the device. The adjustment procedure automatically stores the calibration date on the EEPROM to allow traceability.
4. Reverification–Repeat the verification procedure to ensure that the device is operating within its specifications after adjustment.
These procedures are described in more detail in the following sections.

Initial Setup

Refer to the NI RF Signal Generators Getting Started Guide for information about how to install the software and hardware and how to configure the device in MAX.

Characterizing the Power Splitter
Several procedures in this document require using a splitter that has been characterized to remove error from future measurements. Complete the following steps to characterize a splitter using an NI 5652, power meter, and spectrum analyzer, as shown in Figure 2.
1. Disconnect the NI 5611 LO IN front panel connector from the NI 5652 RF OUT front panel connector.
2. Connect the power meter power sensor to the NI 5652 RF OUT front panel connector.
3. Generate a tone with the NI 5652 with the following NI-RFSG property settings:
· Frequency (Hz): 50 MHz
· Power Level (dBm): ­10 dBm
4. Use the power meter to measure the output power.
5. Repeat steps 3 through 4 for every frequency from 50 MHz to 6.6 GHz in 5 MHz increments, including endpoints. Store the resulting measurements.
6. Disconnect the power sensor from the NI 5652 RF OUT front panel connector.

Caution If you use a cable, it should be as short as possible. The cable should always be used with the splitter for subsequent verification procedures in this document that require a splitter.

7. Connect the power splitter input port to the NI 5652 RF OUT front panel connector without a cable, if possible.

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Caution Remember the port to which the power sensor is connected. The power sensor must be connected to the same port for subsequent procedures in this document.
8. Connect one available port of the power splitter to the power sensor without a cable, if possible.
9. Connect one available end of the power splitter to the 6 dB attenuator. 10. Connect the other available port of the 6 dB attenuator to the spectrum
analyzer RF INPUT front panel connector as shown in Figure 2. 11. Configure the reference level of the spectrum analyzer to ­30 dBm.
The spectrum analyzer is used only for termination.

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NI PXIe-5611 Calibration Procedure

1

2

3

5 6
7

4

8

1 NI 5652 RF Signal Generator 2 Splitter 3 Power Sensor 4 Attenuator

5 Power Meter 6 CH A Connector 7 Spectrum Analyzer 8 RF INPUT Connector
Figure 2. Power Splitter Characterization Setup

12. Repeat steps 3 through 4 for every frequency from 50 MHz to 6.6 GHz in 5 MHz increments, including endpoints. Store the resulting measurements.
13. Subtract the power measurements from step 5 from the measurements in step 12 for each corresponding frequency. Store the resulting calculations. The result is an array representing the loss through the splitter for the entire needed frequency range in 5 MHz increments.

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Note This array is later used to compensate measurements and correct for splitter loss. If you do not find the exact frequency needed in the splitter correction array, use the loss corresponding to the next closest frequency.

You have successfully characterized your splitter.

Verification

This section describes the steps you must follow to verify successful adjustment of the NI 5611.
Verification tests the following NI 5611 specifications: · LO filter response · LO path gain · Modulation impairments · Modulation bandwidth and impairments · RF path gain · Intermodulation products
Verification of the NI 5611 is complete only after you have successfully completed all tests in this section.

Verifying LO Filter Response
Complete the following steps to verify the LO filter response of an NI 5611 module using a spectrum analyzer. 1. Connect the NI 5611 LO OUT front panel connector to the spectrum
analyzer RF INPUT front panel connector. 2. Connect the PXI Express chassis 10 MHz REF IN rear panel connector
to the spectrum analyzer REF OUT rear panel connector. 3. Generate a signal with the following NI-RFSG property settings:
· Frequency (Hz): 85 MHz · Power Level (dBm): 0 dBm · Generation Mode: CW · LO OUT Enabled: Enabled 4. Use the spectrum analyzer to measure the mean fundamental tone power using the following spectrum analyzer parameter settings: · Center Frequency: Frequency from step 3 · Reference level: +5 dBm · Frequency span: 0 Hz

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NI PXIe-5611 Calibration Procedure

· Resolution bandwidth: 500 Hz
· Sweep time: 5 ms
5. Use the spectrum analyzer to measure the mean tone power at the 2nd harmonic frequency using the following spectrum analyzer parameter settings:
· Center Frequency: Frequency from step 3 × 2 · Reference level: +5 dBm
· Frequency span: 0 Hz
· Resolution bandwidth: 500 Hz
· Sweep time: 5 ms
6. Calculate the power level of the harmonic in dBc by subtracting the measured fundamental power from step 4 from the measured harmonic power from step 5.
7. Compare the calculated power level from step 6 to the corresponding limit in Table 1.
8. Repeat steps 3 through 7 for every frequency from 85 MHz to 2.2 GHz in 5 MHz increments, including endpoints.

Table 3. LO Filter Response Verification Test Parameters

Harmonic 2nd (2F)

2nd Harmonic Upper Limits (dBc)

F 100 MHz 100 MHz < F 2.2 GHz

­21

­31

If the results are within the selected test limit, the device has passed this portion of the verification.

Verifying LO Path Gain
Complete the following steps to verify the LO path gain of the NI 5611 module using a power meter. 1. Connect the NI 5611 LO OUT front panel connector to the power
meter. 2. Generate a signal with the following NI-RFSG property settings:
· Frequency (Hz): 85 MHz · Power Level (dBm): 0 dBm · Generation Mode: CW · LO OUT Enabled: Enabled 3. Use the power meter to measure the LO OUT power.

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4. Compare the measured LO OUT output power to the limit in Table 4.
5. Repeat steps 2 through 4 for every frequency from 85 MHz to 6.6 GHz in 10 MHz increments, including endpoints.

Table 4. LO Path Gain Verification Upper Test Limits

LO OUT Power (dBm) 0

As Found LO OUT Power Accuracy Test Limits (dB)
±2.0

As Left LO OUT Power Accuracy Test Limits (dB)
±1.0

If the results are within the selected test limit, the device has passed this portion of the verification.

Verifying Modulation Impairments
Complete the following steps to verify the modulation impairments of the NI 5611 using a spectrum analyzer. 1. Connect the NI 5611 RF OUT front panel connector to the spectrum
analyzer RF INPUT front panel connector. 2. Connect the PXI Express chassis 10 MHz REF IN rear panel connector
to the spectrum analyzer 10 MHz REF OUT rear panel connector on the spectrum analyzer. 3. Generate a single-sideband tone with a +1 MHz offset from the carrier signal with the following NI-RFSG property settings: · Frequency (Hz): 85 MHz · Power Level (dBm): 0 dBm · Generation Mode: Arb Waveform · Reference Clock Source: ClkIn The image appears at 84 MHz, and the carrier leakage at 85 MHz. 4. Use the spectrum analyzer to measure the mean power of the RF output using the following spectrum analyzer parameter settings: · Center frequency: Frequency in step 3 + 1 MHz · Reference level: +5 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 5 ms · Reference clock source: External

Note Zero-span mode shortens test time by avoiding unnecessary frequency sweeping. To obtain the average power, convert the zero-span trace data to linear volts, perform a mean calculation, and then convert the linear volts back to dBm.

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NI PXIe-5611 Calibration Procedure

5. Use the spectrum analyzer to measure the mean power of the image using the following spectrum analyzer parameter settings: · Center frequency: Frequency in step 3 ­ 1 MHz · Reference level: +5 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 5 ms · Reference clock source: External
6. Use the spectrum analyzer to measure the mean power of the carrier using the following spectrum analyzer parameter settings: · Center frequency: Equivalent to the frequency in step 3 · Reference level: +5 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 5 ms · Reference clock source: External
7. Calculate the image suppression ratio (ISR) and carrier suppression ratio (CSR) according to the following formulas and save the values: ISR = Measured Image Power ­ Measured RF Output Power CSR = Measured Carrier Leakage Power ­ Measured RF Output Power
8. Repeat steps 3 though 7 for each LO frequency from 85 MHz to 6.6 GHz in 10 MHz steps, including endpoints.

Note With the baseband set to 1 MHz, 0 dBm single-sideband tone, the RF output is always 1 MHz above the LO frequency, the image is 1 MHz below LO, and the carrier leakage is at LO frequency.

9. Use Table 5 to compare the ISR and CSR from step 7 for each LO frequency.

Table 5. Modulation Impairments Verification Upper Test Limits

LO Frequency (MHz)
85 to 400
400 to 2,500

ISR (dBc) Test Limit
­43
­50

CSR (dBc) Test Limit
­44
­44

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Table 5. Modulation Impairments Verification Upper Test Limits

LO Frequency (MHz)

ISR (dBc) Test Limit

CSR (dBc) Test Limit

2,500 to 5,500

­46

­44

5,500 to 6,600

­43

­41

If the results are within the selected test limit, the device has passed this portion of the verification.

Verifying Modulation Bandwidth and Impairments
Complete the following steps to verify the modulation bandwidth performance and modulation impairments of the NI 5611 using a spectrum analyzer. 1. Connect the NI 5611 RF OUT front panel connector to the spectrum
analyzer RF INPUT front panel connector. 2. Connect the PXI Express chassis 10 MHz REF IN rear panel connector
to the spectrum analyzer 10 MHz REF OUT rear panel connector on the spectrum analyzer. 3. Generate an I/Q tone at ­50 MHz offset from the carrier with the following NI-RFSG property settings: · Frequency (Hz): 200 MHz · Power Level (dBm): 0 dBm · Generation Mode: Arb Waveform · Reference Clock Source: ClkIn 4. Use the spectrum analyzer to measure the mean output power of the RF output using the following spectrum analyzer parameter settings: · Center frequency: frequency in step 3 + offset in step 3 · Reference level: +5 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 5 ms · Reference clock source: External 5. Use the spectrum analyzer to measure the mean output power of image using the following spectrum analyzer parameter settings: · Center frequency: frequency in step 3 ­ offset in step 3 · Reference level: +5 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz

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NI PXIe-5611 Calibration Procedure

· Sweep time: 5 ms · Reference clock source: External 6. Calculate the ISR according to the following formula and save the values: ISR = Measured Image Power ­ Measured RF Output Power
7. Repeat steps 3 through 6 for every offset frequency from ­50 MHz to +50 MHz in 5 MHz increments while keeping the LO frequency fixed.

Tip Set the NI-RFSG Generation Mode property to CW to generate a 0 Hz offset. The ISR with a 0 Hz frequency offset cannot be measured, and the 0 Hz data point can be ignored.

8. Calculate the relative modulation bandwidth flatness by subtracting the RF output power measured at 0 Hz offset from the RF output powers measured at each of the other offset frequencies.
9. Compare each value calculated in step 8 to the limits in Table 6 and compare only the ISR values calculated for offset frequencies between ­10 MHz and 10 MHz in step 5 to the limits in Table 7.

Note Values calculated for offset frequencies less than ­10 MHz and greater than 10 MHz are not specified and do not have test limits.

10. Repeat steps 3 through 9 for each LO frequency in Table 6.

Table 6. Modulation Bandwidth Impairment Verification Test Limits

LO Frequency (GHz)
0.2

Modulation Bandwidth Test Limits (dB)

Maximum

Minimum

3

­3

2.4

3

­3

4.0

3

­3

5.8

3

­3

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Table 7. Modulation Bandwidth Impairment Verification Test Limits for Offset Frequencies Between ­10 MHz and +10 MHz

LO Frequency (GHz)

Test Limits ISR (dBc)

0.2

­41

2.4

­48

4.0

­45

5.8

­41

If the results are within the selected test limit, the device has passed this portion of the verification.

Verifying RF Path Gain
Complete the following steps to verify the RF path gain of the NI 5611 using a power meter, rubidium frequency standard, spectrum analyzer, power splitter, and 6 dB attenuator.

Note The attenuator is placed in front of the spectrum analyzer to improve the spectrum analyzer return loss. The power splitter must be characterized so that you can account for its loss. Refer to the Characterizing the Power Splitter section for more information about how to characterize your power splitter.

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NI PXIe-5611 Calibration Procedure

5

1

34

2

6

7

8 10
9 2

11

1 NI 5450 Arbitrary Waveform Generator 2 Connection from NI PXI Express
REF IN Rear Panel Connector to Spectrum Analyzer REF OUT Rear Panel Connector 3 NI 5611 I/Q Modulator 4 NI 5652 RF Signal Generator 5 Power Sensor

6 Power Splitter 7 Attenuator 8 Power Meter 9 Spectrum Analyzer 10 CH A Connector 11 RF INPUT Connector

Figure 3. Connecting Hardware to Verify RF Path Gain
1. Connect the input port of the power splitter to the NI 5611 RF OUT front panel connector.
2. Connect the PXI Express chassis 10 MHz REF IN rear panel connector to the spectrum analyzer 10 MHz REF OUT rear panel connector.

Caution The port used to connect the power splitter to the power sensor in step 8 of the Characterizing the Power Splitter section must be the same port used to connect the power splitter to the power meter in step 3 of this section.

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3. Connect one available port of the power splitter to the power meter.
Caution The port used to connect the power splitter to the 6 dB attenuator in step 9 of the Characterizing the Power Splitter section must be the same port used to connect the power splitter to the power meter in step 4 of this section.
4. Connect one available port of the power splitter to the 6 dB attenuator. 5. Connect one available port of the 6 dB attenuator to the spectrum
analyzer RF INPUT front panel connector. 6. Disconnect the NI 5450 CLK IN front panel connector from the
NI 5652 REF IN/OUT front panel connector. 7. Generate a single-sideband tone with a +1 MHz offset from the carrier
with the following NI-RFSG property settings: · Frequency (Hz): 85 MHz · Power Level (dBm): 5 dBm · Generation Mode: Arb Waveform · Reference Clock Source: ClkIn 8. Use the power meter to measure power splitter-compensated output power. 9. Repeat steps 7 through 8 for every frequency from 85 MHz to 6.6 GHz in 20 MHz increments, including endpoints. 10. Set the NI-RFSG Power Level property to 0 dBm, and repeat steps 7 through 9. 11. Set the NI-RFSG Power Level property to ­30 dBm, and repeat steps 7 through 9, measuring the power using both the power meter and spectrum analyzer. Use the following parameter settings for the spectrum analyzer: · Center frequency: frequency in step 7 + 1 MHz · Reference level: ­30 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 20 ms · Reference clock source: External · Attenuation: 5 dB · Preamplifier: On 12. Use the power meter measurements to calculate a correction for the spectrum analyzer inaccuracies and attenuator loss.

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NI PXIe-5611 Calibration Procedure

13. Set the NI-RFSG Power Level property to ­60 dBm, and repeat steps 7 through 9 using only the spectrum analyzer and its measured correction to measure the power accuracy using the following spectrum analyzer parameter settings: · Center frequency: frequency in step 7 + 1 MHz · Reference level: ­30 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 20 ms · Reference clock source: External · Attenuation: 5 dB · Preamplifier: On
14. Set the NI-RFSG Power Level property to ­90 dBm and repeat steps 7 through 9 using only the spectrum analyzer and its measured correction to measure the power accuracy using the following spectrum analyzer parameter settings: · Center frequency: frequency in step 7 + 1 MHz · Reference level: ­30 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 200 ms · Reference clock source: External · Attenuation: 5 dB · Preamplifier: On
15. Compare the measured values from steps 7 through 14 to the corresponding limits in Table 8.

Table 8. RF Path Gain Verification Test Limits

Output Power (dBm) 5

Power Accuracy Test Limits (dB) ±0.75

0

±0.75

­30

±0.75

­60

±0.75

­90

±0.75

If the results are within the selected test limit, the device has passed this portion of the verification.

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Adjustment

Following the adjustment procedure automatically updates the calibration date and temperature in the EEPROM of the NI 5611. The calibration date is also updated when you call the niRFSG Initialize External Calibration and niRFSG Close External Calibration VIs.
Adjustment involves the following NI 5611 procedures: · LO filter response · LO path gain · Modulation impairments · RF path gain

Adjusting LO Filter Response
This adjustment yields a reduced LO second harmonic. Complete the following steps to adjust the LO filter response of the NI 5611 using a spectrum analyzer.
1. Connect the NI 5611 LO OUT front panel connector to the spectrum analyzer RF INPUT front panel connector.
2. Connect the PXI Express chassis 10 MHz REF IN rear panel connector to the spectrum analyzer 10 MHz REF OUT rear panel connector on the spectrum analyzer.
3. Call the niRFSG Initialize External Calibration VI.
4. Call the niRFSG Initialize LO Filter Calibration VI.

Note The Filter to Calibrate parameter on the niRFSG Initialize LO Filter Calibration VI is by default set to All Filters. If you set the Filter to Calibrate parameter to another filter setting, you must repeat steps 4 through 8 for each filter.

5. Call the niRFSG 5611 Configure LO Filter Calibration VI. 6. Use the spectrum analyzer to measure the mean output power using the
following spectrum analyzer parameter settings: · Center frequency: frequency specified by the Frequency to
Measure (Hz) parameter of the niRFSG 5611 Configure LO Filter Calibration VI · Reference level: +5 dBm · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 5 ms

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NI PXIe-5611 Calibration Procedure

7. Call the niRFSG 5611 Adjust LO Filter Calibration VI, and pass the value measured in step 6 to the Measured LO OUT Power (dBm) parameter.
8. Repeat steps 5 through 7 in a loop until the LO Filter Calibration Complete parameter returns a value of TRUE.
9. Call the niRFSG Close External Calibration VI to close the session and store the results to the EEPROM on the NI 5611.
Adjusting LO Path Gain
This adjustment yields accurate power levels reaching both the internal modulators and the LO OUT connector on the NI 5611. Complete the following steps to calibrate the LO path gain on the NI 5611 using a power meter. 1. Connect the NI 5611 LO OUT front panel connector to the power
meter. 2. Call the niRFSG Initialize External Calibration VI. 3. Call the niRFSG 5611 Initialize LO Gain Calibration VI.
Note The Filter to Calibrate parameter on the niRFSG Initialize LO Gain Calibration VI is by default set to All Filters. If you set the Filter to Calibrate parameter to another filter setting, you must repeat steps 3 through 7 for each filter.
4. Call the niRFSG 5611 Configure LO Gain Calibration VI. 5. Use the power meter to measure the output power at the frequency
specified by the Frequency to Measure (Hz) parameter of the niRFSG 5611 Configure LO Gain Calibration VI. 6. Call the niRFSG 5611 Adjust LO Gain Calibration VI, and pass the value measured in step 5 to the Measured LO OUT Power (dBm) parameter. 7. Repeat steps 4 through 6 until the LO Gain Calibration Complete parameter returns a value of TRUE. 8. Call the niRFSG Close External Calibration VI to close the session and store the results to the EEPROM on the NI 5611.

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Adjusting Modulation Impairments
This adjustment measures and corrects the NI 5611 RF fundamental, carrier, and image tones until the carrier and image tones are sufficiently suppressed.
Complete the following steps to calibrate the modulation impairments of the NI 5611 using a spectrum analyzer. 1. Connect the NI 5611 RF OUT front panel connector to the spectrum
analyzer RF INPUT front panel connector. 2. Connect the PXI Express chassis 10 MHz REF IN rear panel connector
to the spectrum analyzer 10 MHz REF OUT rear panel connector. 3. Call the niRFSG Initialize External Calibration VI. 4. Call the niRFSG 5611 Initialize Impairment Calibration VI. 5. Call the niRFSG 5611 Configure Impairment Calibration VI.
Note The default behavior of the niRFSG 5611 Configure Impairment Calibration VI is to calibrate all filters. If you choose to calibrate a single filter, repeat the entire RF path calibration procedure for each of the eight filters to complete a full calibration.
6. Use the spectrum analyzer to measure the mean tone power using the following spectrum analyzer parameter settings: · Center frequency: Value specified by the Frequency to Measure (Hz) parameter of the niRFSG 5611 Configure LO Filter Calibration VI · Reference level: Value specified by the Spectrum Analyzer Reference Level (dB) parameter of the niRFSG 5611 Configure Impairment Calibration VI · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 5 ms
7. Call the niRFSG 5611 Adjust Impairment Calibration VI, and pass the measurement from step 6 to the Measured RF OUT Power (dBm) parameter of the niRFSG 5611 Adjust RF Gain Calibration VI.
8. Repeat steps 5 through 7 until the Impairment Calibration Complete parameter returns a value of TRUE.
9. Call the niRFSG Close External Calibration VI to close the session and store the results to the EEPROM on the NI 5611.

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NI PXIe-5611 Calibration Procedure

Adjusting RF Path Gain
This adjustment yields accurate power levels out of the NI 5611 RF OUT front panel connector. Complete the following steps to properly connect the devices, as shown in Figure 4, to adjust RF path gain.
4

1

23

5

Reverse Pwr +30 dBm MAX

TTL

NI PXIe-5450 400 MS/s I/Q Signal Generator

NI PXIe-5611 I/Q Vector Modulator

ACCESS

ACTIVE

CLK IN

CH 0 +

ACCESS

ACTIVE

85 MHz 6.6 GHz RF OUT
I+ I+

5 Vp-p MAX, 50
CLK OUT

50
CH 0 ­

PLS MOD I­ I­

0.7 Vp-p NOM
PFI 0

50
CH 1 +

LO IN Q+ Q+

LVT T L
PFI 1
LVT T L

50
CH 1 ­

LO OUT Q­ Q­

50 ESD SENSITIVE

RF PORTS ±5 VDC MAX

+18 dBm MAX

+18 dBm MAX

7 8
9

6

10

1 NI 5450 Arbitrary Waveform Generator 2 NI 5611 I/Q Modulator 3 NI 5652 RF Signal Generator 4 Power Sensor 5 Power Splitter

6 Attenuator 7 Power Meter 8 CH A Connector 9 Spectrum Analyzer 10 RF INPUT Connector

Figure 4. Connecting Hardware to Adjust RF Path Gain

1. Connect the input port of the power splitter to the NI 5611 RF OUT front panel connector.

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2. Connect the PXI Express chassis 10 MHz REF IN rear panel connector to the spectrum analyzer 10 MHz REF OUT rear panel connector.
3. Connect one available port of the power splitter to the power meter. 4. Connect one available port of the power splitter to the 6 dB attenuator. 5. Connect one available port of the 6 dB attenuator to the spectrum
analyzer RF INPUT front panel connector.
Note For best results, do not use any cables between the NI 5611, power splitter, and power sensor. Connect these devices directly together.
6. Call the niRFSG Initialize External Calibration VI. 7. Call the niRFSG 5611 Initialize RF Gain Calibration VI. 8. Call the niRFSG 5611 Configure RF Gain Calibration VI, and set the
Instrument Transition Threshold (dBm) parameter to the power level equal to the bottom of the power meter’s accurate range.
Note The default behavior of the niRFSG 5611 Configure RF Gain Calibration VI is to calibrate all filters. If you choose to calibrate a single filter, repeat the entire RF path calibration procedure on each of the eight filters to complete a full calibration.
9. Configure the spectrum analyzer using the following spectrum analyzer parameter settings: · Center frequency: value specified by the Frequency to Measure (Hz) parameter of the niRFSG 5611 Configure RF Gain Calibration VI · Reference level: value specified by the Spectrum Analyzer Reference Level (dB) parameter of the niRFSG 5611 Configure Impairment Calibration VI · Frequency span: 0 Hz · Resolution bandwidth: 500 Hz · Sweep time: 20 ms · Attenuation: 5 dB · Preamplifier: On
10. Using the instrument(s) specified by the Measurement Instrument parameter of the niRFSG 5611 Configure Impairment Calibration VI, measure the mean power of the generated tone at the frequency specified by the Frequency to Measure (Hz) parameter of the niRFSG 5611 Configure RF Gain Calibration VI.

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Note If the instrument specified is Power Meter & Spectrum Analyzer, then you must measure the power with the power meter and the spectrum analyzer simultaneously. These measurements are used to correct the spectrum analyzer’s inaccuracy.
11. Compensate only the power meter measurement for the loss of the power splitter by subtracting the loss measured in the Characterizing the Power Splitter section from the power meter measurement in step 10 in this section.
12. Call the niRFSG 5611 Adjust RF Gain Calibration VI, and pass the measurements from step 11 to the Power Meter Measurement (dBm) and/or Spectrum Analyzer Measurement (dBm) parameter.
13. When the spectrum analyzer measures a level of ­110 dBm, increase the sweep time for each measurement to 200 ms. The sweep time can return to 20 ms when the Measurement Instrument parameter of the niRFSG 5611 Configure RF Gain Calibration VI returns a value of Power Meter. The sweep time should alternate several times between 20 ms and 200 ms as these conditions are met.
Note Only the instrument indicated by the Measurement Instrument parameter is actually used. Values passed for the inactive instrument are ignored. The power meter is used for higher power measurements, and the spectrum analyzer is used for lower power measurements.
14. Repeat steps 8 through 12 until the RF Gain Calibration Complete parameter returns a value of TRUE. Additional averaging is required on the spectrum analyzer to minimize the effects of noise at the lower power levels. After a level of ­90 dBm or less is measured, increase the sweep time to 200 ms for the remaining measurements of the procedure.
15. Call the niRFSG Close External Calibration VI to close the session and store the results to the EEPROM on the NI 5611.
You have finished adjusting the NI 5611. Repeat the Verification section to reverify the performance of the NI 5611 after adjustments.

NI PXIe-5611 Calibration Procedure

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ni.com

Appendix A: Calibration Utilities
NI-RFSG provides a full complement of calibration utility VIs. You can use utility VIs to retrieve information about adjustments performed on the NI 5611, change the calibration password, and store small amounts of information in the onboard EEPROM. The Calibration Utility palette includes the following VIs: · niRFSG Change External Calibration Password VI · niRFSG Close External Calibration VI · niRFSG Get External Calibration Last Date And Time VI · niRFSG Initialize External Calibration VI · niRFSG Set External Calibration Last Date and Time VI
Calibration VI References
The VIs used in this procedure, including all calibration VIs and functions, are documented in the NI-RFSG VI Reference, which you can access from the NI RF Signal Generators Help at Start»All Programs»National Instruments»NI- RFSG»Documentation.

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Where to Go for Support
The National Instruments Web site is your complete resource for technical support. At ni.com/support you have access to everything from troubleshooting and application development self-help resources to email and phone assistance from NI Application Engineers.
A Declaration of Conformity (DoC) is our claim of compliance with the Council of the European Communities using the manufacturer’s declaration of conformity. This system affords the user protection for electromagnetic compatibility (EMC) and product safety. You can obtain the DoC for your product by visiting ni.com/certification. If your product supports calibration, you can obtain the calibration certificate for your product at ni.com/calibration.
National Instruments corporate headquarters is located at 11500 North Mopac Expressway, Austin, Texas, 78759-3504. National Instruments also has offices located around the world to help address your support needs. For telephone support in the United States, create your service request at ni.com/support and follow the calling instructions or dial 512 795 8248. For telephone support outside the United States, contact your local branch office:
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Mar10

References

• Test and Measurement Systems, a part of Emerson - NI
• Test and Measurement Systems, a part of Emerson - NI
• Product Certifications - NI
• Software and Driver Downloads - NI
• Instrument Driver Network (IDNet) - NI
• Product Documentation - NI
• Contact Us - NI
• Log In - National Instruments
• NI Services - NI
• Support - NI
• NI Trademarks and Logo Guidelines - NI
• Software and Driver Downloads - NI
• Product Certifications - NI
• Contact Us - NI
• Log In - National Instruments
• NI Services - NI
• Support - NI
• PXI-5650 National Instruments Analog Signal Generator | Apex Waves

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