Saluki SER300 SER Series EMI Receiver User Manual

SER Series EMI Receiver
User Manual
SER300/SER2000/SER3600
Saluki Technology Inc.

SER300 SER Series EMI Receiver’

Security requirements
General Safety Summary
Know the following safety precautions to avoid injury and prevent damage to this product or any products connected to it. To avoid possible dangers, please use this product in accordance with the regulations.
Use the correct power cord
Only use the power cord approved for this product in your country.
Ground the product
This product is grounded through the protective earth of the power cable. To avoid electric shock, before connecting any input or output terminals of this product, please ensure that the grounding terminal of the power cable of this product is reliably connected to the ground terminal of the protective connection.
Properly connect the probe
Proper use of the probe, the ground wire of the probe is the same as the ground, do not connect the ground wire to high voltage.
View All Terminal Ratings
In order to avoid fire and the impact of excessive current, please check all the ratings and marking instructions on the product. Please refer to the product manual for the detailed information of the rating when connecting the product.
Use suitable overvoltage protection
Make sure that no overvoltage, such as that caused by lightning, reaches the product. Otherwise, the operator may suffer from electric shock again.
Do not open the cover to operate
Do not operate this product with the instrument case open.
Do not insert foreign objects into the exhaust vent of the fan
Do not insert foreign objects into the air outlet of the fan to avoid damage to the instrument.
Use the proper fuse
Only use fuses with specifications specified for this product.
Avoid circuit exposure
Do not touch exposed connections and components when power is on.
Maintain proper ventilation
Poor ventilation can cause the temperature of the instrument to rise, which can cause damage to the instrument. Keep well ventilated when in use, and check the vents and fans regularly.
Do not operate in wet environment
To avoid the risk of short circuit or electric shock inside the instrument, do not operate the instrument in wet environment.
Please keep the product surface clean and dry
To avoid dust and moisture in the air from affecting the performance of the instrument, please keep the surface of the product clean and dry.
Anti-static protection
Static electricity will cause damage to the instrument, and the test may be performed in an anti-static area. Before connecting a cable to an instrument, briefly ground its inner and outer conductors to discharge static electricity.
Pay attention to handling safety
In order to prevent the instrument from slipping during transportation and causing damage to the buttons, knobs or interfaces on the panel of the instrument, please pay attention to the safety of transportation.

General inspection
Check shipping packaging
If the shipping packaging is damaged, keep the damaged packaging and shockproof material until the shipment has been fully inspected.
If the instrument is damaged due to transportation, the sender and the carrier will contact each other for compensation. Saluki does not provide free repair and replacement.
Check the whole machine
If there is mechanical damage or missing, or the instrument fails the electrical performance test. Please contact Saluki Technology Inc. or your distributor.
Check the accessories
Please check the accompanying accessories according to the packing list. If there is any loss or missing, please contact Saluki Technology Inc.

Power connection
Please use the power cord provided in the accessories to connect the spectrum analyzer to the AC powe supply.
This instrument supports 100V-24V, 45-440Hz AC power supply. When the spectrum analyzer is connected to the AC power supply through the power cord, the instrument automatically adjusts to the correct voltage range, no need to manually select the voltage range.

Notice:
To avoid electric shock, make sure the instrument is properly grounded.
Maintenance and Cleaning
Maintainance
Do not place the instrument in a place exposed to sunlight and humidity for a long time.
Cleaning
Please clean the instrument frequently according to usage conditions.
Methods as below:

1. Disconnect the power
2. ipe the exterior of the instrument with a soft cloth soaked in mild detergent or water. Be careful not to scratch the LCD display.

Notice:
Do not let any corrosive liquid get on the instrument, so as not to damage the instrument.

Overview
SER series is a small size, light weight, highly integrated portable EMI receiver. It has an easy-to-operate keyboard layout, a high-definition color LCD display, and rich remote communication interfaces, and can be widely used in many fields such as education science, enterprise research and development, and industrial production.

Key features:
The frequency range is 1kHz—300MHz/2GHz/3.6GHz
There are multiple detection functions
There are various EMI measurement standards
Best Sensitivity-145dBm
8.4-inch bright TFT LCD display
Universal USB, LAN for easy control
Weight less than 6.5kg

Receiver Introduction

1.1 Front panel
The EMI receiver provides the user with a simple and well-defined front panel for basic operation. panel It includes a knob and function keys, and the function of the knob is similar to that of other instruments. There are 7 function soft keys on the right side of the display, keys, through which different options of the current menu can be set. Other keys are function keys, through them, it is possible to enter different function menus or directly obtain specific function applications.

1. Power switch
2. USB interface
3. Tracking source output terminal| 4. Knob
5. RF input terminal
6. parameter input area| 8. System function area
7. Cursor keypad
9. soft menu setting area
10. display screen
---|---|---

1.2 Rear panel

1.RS232 interface
2.LAN interface
3.10MHz reference signal input/output connector
4.VGA interface| 5.USB interface
6.headphone jack, audio output
7.EMI receiver power input socket
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1.3 Button control area

1.Common function key area
2.Parameter setting keypad| 3.Cursor measurement function key area
4.System function key area
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1.4 Detailed Description of Function Keys

Function key detailed table

Analyzer Setup Keypad
【FREQ】| Frequency parameter setting| center frequency, start frequency, stop frequency, frequency step (from manual/manual), frequency offset (default 0Hz), frequency reference (internal internal/external), LF channel (on/off)
【SPAN】| Span setting| Span (automatic/manual), full span, zero span, previous span
【AMPT】| Amplitude setting| Reference level, attenuator, scale/div (default 10dB), scale Type (Linear/Logarithmic), Reference Bias (0dB), Reference units (dBm, dBuV, dBpW, dBmW, dBmV, W, V), pre-amplification (automatic/manual)
【AUTO】| Auto Search| Automatically test RF IN 50ÿ input RF signal
【BW】| Resolution Bandwidth Set| resolution bandwidth (auto/manual), resolution step (default/continuous continued), video bandwidth (on/off)
【Sweep】| Scanning Time Set| the scanning time (automatic/manual), single scanning, continuous scanning, Scan point settings
【Trig】| Trigger mode setting| automatic, video (-20.00dB), external (rising edge/falling edge)
【Trace】| Trace settings| Trace (1, 2, 3), Refresh, Max Hold, Min Hold, Blanking, viewing, trace calculation
【Detector】| Detection mode| setting automatic, normal, positive peak, negative peak, sampling
【Display】| Display settings| Full screen display, window scaling (on/off), display lines -25dBm (on/off), grid (on/off), amplitude Ruler (on/off), label (on/off)
Measurement function keypad
【Meas】| Measurement function settings| time spectrum (on/off), adjacent channel power (on/off), Channel power (on/off), occupied bandwidth (on/off)
【Meas etup】| Measuring settings| Default state, cannot be replaced
Frequency standard function key are
【Marker】| Frequency marker indication setting| key frequency marker (1, 2, 3, 4, 5), trace (1, 2, 3), normal, Difference, Off, All Off, Marker List (On/Off)
【Marker ctn】| Frequency marker function key| Function off, NdB3.00 (on/off), frequency standard noise (on on, off), frequency counting (on/off)
【Marker→】| Frequency marker indication change key| Frequency marker center frequency, frequency marker frequency step, frequency marker start Frequency, Frequency StandardÿStop Frequency, Frequency StandardÿReference Level
【Peak】| Peak measurement key| Maximum search, next peak, left peak, right peak, minimum Value search, peak search (on/off)
System Function Keypad
【Preset】| System reset| System information, configuration I/O, power on/reset, date/time, Backlight adjustment, user calibration, system service, screen refresh (on on/off), 75ÿ impedance compensation 0.00dB (on/off) storage (screenshots, trace data, user status)
【System】| system setting key| paper size, printing language, printing type (black and white/color), Orientation (Landscape/Portrait)
【Print Setep】| Print setup| EMI receivers, spectrum analyzers, network measurements, filter simulations real
【Mode】| mode selection key| EMI receivers, spectrum analyzers, network measurements, filter simulations real

1.5 Parameter input interface

1.Knob
2.Backspace key| 3.Confirm key
4.Number keypad
5.Arrow keys
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The 3 modes of the user interface are as follows:

1. Spectrum analyzer user interface
2. EMI receiver user interface
3. Network measurement interface

Introduction to EMI Receiver

2.1 EMI Receiver
2.1.1 EMI receiver instrument interface

Test report style: 2.1.2 EMI Receiver Test Standards

RE102  (RE102-1,  RE102-2,  RE102-3)
2| GJB151B| CE102  (28V,  115V,  220V)
RE102  (ships,  submarines,  air,  ground)
3| GB17743| GB17743  conduction,  GB17743  radiation
4| GB9254| Conduction:  GB9254A,  GB9254B
Radiation:  GB9254A,  GB9254B
5| EN55014| Conduction:  power  terminal,  below  700W,  700W-1000W,  above 1000W
Harassment:  power  terminal,  below  700W,  700W-1000W,  above  1000W
6| EN55015| Conduction:  power  terminal,  below  700W,  700W-1000W,  above 1000W
Harassment:  power  terminal,  below  700W,  700W-1000W,  above  1000W
7| FCC Part 15B| FCC  conduction
8| JAPAN lamps| Conduit,  Harassment
9| JAPAN home appliance| conduction:  power  terminal,  below  700W,  700W- 1000W,  above  1000W
Harassment:  power  terminal,  below  700W,  700W-1000W,  above  1000W
10| GB4824| Conduction:  ≤20kVA,  >20kVA;
11| EN55011| Conduction

2.1.3 Common EMI Receiver Operations
2.2.3.1 Common parameter settings
Common parameters of the receiver include: start frequency, stop frequency, attenuation, preamplification, dynamic range, bandwidth, Measurement time, scan mode, etc.
【Start Frequency】
Operation steps: [FREQ]→[Start Frequency], the default is 30MHz, after adjustment, the frequency spectrum displays the area frequency rate range auto-adjust
【Stop frequency】
Operation steps: [FREQ]→[Stop Frequency], the default is 1GHz, after adjustment, the spectrum displays the regional frequency auto range adjustment
【attenuation】
Operation steps: [AMPT] →[Attenuation], the default is 9dB, the range of change is 0~39dB, 3dB step
【Pre-amplification】
Operation steps: [AMPT] → [Pre-amplification], the default is off, and the gain can be increased by 20dB after opening
【Dynamic Range】
The spectrum display area displays the range, which can display 100dB dynamic range by default, and the minimum level is 0dBuV.
Operation steps: [AMPT] → [level range], the default is 100dB, and the adjustable range is 10dB~200dB
[AMPT] → [Minimum level], default 0dBuV , Adjustable range -93dBuv~297dBuV
Operation steps: [BW] → [Resolution Bandwidth] Receiver mode provides 10Hz/100Hz/200Hz/1kHz/9kHz/10kHz/100kHz/120kHz/1MHz total 9 file resolution Bandwidth, you can cycle through the up and down arrow keys, and the menu area displays commonly used 200Hz/9kHz/120kHz/1MHz four-speed resolution bandwidth
【measure time】
Receiver measurement time range: 100us~100s
Operation steps: 【Meas】→【Measuring time】, the default is 10ms
【Scan mode】
Operation steps: [Sweep] → [List Sweep] / [Current Settings] [List Scan] mode provides 10 independent measurement intervals, and each interval can be set for different measurements Parameters, executed in interval order during measurement
【Current setting】Quick measurement, equivalent to an interval measurement

2.2.3.2 Fixed frequency measurement
Fixed frequency measurements are automatically activated when not scanning, and automatically hide after starting a scan or measurementThe fixed frequency is determined by the receiving frequency, and the maximum value (MAX), quasi-peak value (QPK), Average value (AVG), effective value (RMS) four kinds of detection results display, each detection value has a maximum hold Hold function in dBuV. As shown in the figure above, the maximum value (MAX) detection, the current real-time value is 47.56dBuV, The historical maximum is 48.46dBuV. After the receiving frequency is modified, the maximum hold value is automatically reset.

2.2.3.3 Fast scan/measurement
EMI receiver quick measurement is divided into single-segment measurement and multi-segment measurement.
Single-segment measurement: scan with the parameters currently set by the receiver. The scanning step is automatic according to the IF bandwidth The start and end frequency can be set by [FREQ] menu; the resolution bandwidth can be set by [BW] Certainly.
Operation steps, first [Sweep] → [Current Settings] → [Start Scanning], and then set other
Related parameters, such as frequency [FREQ], amplitude [AMPT], bandwidth [BW], measurement time [Meas], Trace [Trace], detector [Detector].
ÿ Multi-segment measurement: The receiver mode has built-in 10 interval measurements with adjustable steps, and each interval can be carried out Measurement of different parameters

Interval parameters can be set independently, up to 10 intervals can be set, after the setting is completed, click 【Sweep】→ 【Column】
Table scan] → [Start scan] to complete multi-segment scan.
Default interval 1 parameter

| Zone 1| Zone 2| Zone 3| Zone 4| Zone 5
---|---|---|---|---|---
Scan start| 1KHz| | | |
Scan termination| 300MHz| | | |
step| 40kHz| | | |
Resolution bandwidth| 120kHz| | | |
Measurement time| 100us| | | |
Attenuation| 9dB| | | |
Preamp| off| | | |

Description of parameters in the above figure: start frequency 1kHz, stop frequency 300MHz, minimum level 0dBuV, level
Display range 100dB, continuous scanning. Specific parameter input is mainly by means of up and down direction keys and pulse rotation button to switch and input. in,
Scan start: set the scan frequency at the start of the interval, and modify it by inputting the number keys
Scanning termination: set interval termination scanning frequency, number key input modification
Stepping: currently in automatic mode, without modification, it will be automatically assigned by the system
Resolution bandwidth: 6dB resolution bandwidth selection, switch by [Enter] Measuring time: scanning time of stepping frequency, number key input modification
Attenuation: 0~39dB input range, 3dB step, can be modified by numeric key input, or by [Enter] to switch
Pre-amp: Built-in 20dB amplifier switch, open when measuring small signals

2.1.3.4 Standard measurements

1. EMI receiver system entry steps
   Take the GJB151B CE102 test as an example:
   [Mode]→[EMI]→[Meas]→[Standard]→[CE102]→[220V] NOTE: Follow these steps for other standard inputs.

2. Standard curve marking and viewing:
   [Stop scanning]→[FREQ][Receive frequency change (check mark)][Start scanning]

3. Limit line editing: You can edit the measurement standard limit line by yourself
   [Meas Setup][New/Edit]Name]Value[Add/Insert]Save

4. Compensation setting: You can input antenna coefficient, near-field probe calibration coefficient, LISN insertion loss, etc.
   [Mode]→[EMI]→[Meas]→[Compensation]

2.2 Network measurement introduce:
Network measurement is a port measurement, using the signal source and receiving source inside the instrument to complete the port connection test, Specifically, it can directly test the filter, the insertion loss value of the cable, the magnification of the amplifier, etc.
Enter the operation interface:
[Mode]→[Network Measurement]→[FREQ]→[Output Power]→[Scan Points] Use the output terminal RF OUT 50[ input and RF OUT 50] terminals to make a test. See 3.3 for detailed operation section introduction.

EMI Receiver Measurements

3.1 Measurement items under EMI state
3.1.1 Main functions

1. Able to use the instrument to check military standards (GJB151A, GJB151B), national standards (GB17743, GB9254, GB4824),European standard (EN55014, EN55011), FCC (FCC Part 15B), Japanese standard (JAPAN lamps, JAPAN home Electricity) and other standards for testing.
2. Ability to self-edit measurement standard limits

3.1.2 EMI receiver menu structure

3.1.3 Standard tests under EMI receiver
3.2.3.1 GJB151A conducted emission test
In this test example, the GJB151A CE102 220V test is used as an example. After setting up the experimental platform, directly
For the conduction data test of EUT, the CE102 conduction emission test platform is shown in the figure below:![Saluki SER300 SER Series EMI Receiver

• block diagram](https://manuals.plus/wp-content/uploads/2023/12/Saluki-SER300 -SER-Series-EMI-Receiver-block-diagram.jpg)

Figure 3.11 Build CE102 test platform
Figure 3.12 Specific Field Test Connection Diagram
Line Impedance Stabilization Network (LISN) Instructions for Use WARNING

1. When using the power supply impedance to stabilize the network, the ground terminal on the rear panel of the instrument must be connected to the reference ground.
   Reliable connection.

2. Only when the equipment under test (EUT) works normally, the monitoring of the power supply impedance stabilization network Connect the terminal to the input terminal of the spectrum analyzer. In order to protect the safety of the test equipment, avoid the signal too If it is too strong and burns out the receiver, a 20dB attenuator should be added to the receiver input.

3. When the monitoring terminal of the source impedance stabilization network (LISN) is connected to the receiver, do not Power off the device under test! Because when the current is cut off suddenly, the 50μH inductance in LISN may cause overvoltage spikes and damage the receiver.

4. When the monitoring end of the power supply impedance stabilization network is not connected to the receiver, it should be connected to a monitoring end 50Ω load.

5. After each measurement, first unplug the connecting cable between the monitoring terminal of LISN and the spectrum analyzer, Then turn off the power of the spectrum analyzer, and finally turn off the power of the device under test.

6. Because there is a relatively large filter capacitor in the power supply impedance stabilization network, it cannot be used in leaky on the electrical protection grid. If it is used in a general laboratory, it must be transformed by power isolation The transformer feeds the mains impedance stabilization network.

After setting up the experimental test platform, follow the steps below to test:

1. After booting and warming up for 25 minutes, the system will automatically enter the EMI receiver system interface;
2. Test standard selection. PressÿMeasÿto select the EMC test standard, and use the softkeys on the interface to directly select Select [Standard], select [GJB151A] in the standard list, select [CE102] in the national military standard list, according to The DUT is required to select the [220V] reference line, and the test interface under this standard is as follows:

|
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3.1.3.1 GJB151B radiated emission test
In this test example, the GJB151B RE102 test is used as an example. After setting up the experimental platform, directly test the The EUT data test, RE102 launch test platform is shown in the figure below:

The specific test steps under this standard are as follows:

1. After booting and warming up for 25 minutes, the system will automatically enter the EMI receiver system interface;
2. Test standard selection. PressÿMeasÿto select the EMC test standard, and use the softkeys on the interface to directly select Select [Standard], select [GJB151B] in the standard list, select [RE102] in the national military standard list, according to The DUT requires to select the limit value, for example, select [Ground] limit value, the standard test interface is as follows:

After starting the test, the test curve is shown in the figure below:

3.2 Operation of network measurement
ER series EMI receivers have network measurement function and are mainly used for amplitude-frequency characteristic measurement. can be measured Insertion loss, isolation, and amplifier gain for passive networks such as filters, attenuators, and cabling wait. For example, to measure the performance of the filter: connect the output of the signal tracking source to the input of the filter, and then connect the filter
Connect the output terminal of the oscilloscope to the input terminal of the spectrum analyzer to measure the filtering characteristics of the filter.

Measurement methods:
Setting parameters
—Press [Mode]key to select [Network Measurement] —Press[SPAN]key to adjust the span to the required width (eg. 200MHz)

1. Use an adapter (short connector) to connect the tracking generator output cable to the spectrum input cable, Open the network measurement function, press the arrow keys【⬆】【⬇】or number keys to change the output power, reference level, Scan time and scan points.
   —Press the [Normalization] key, and the display will display a straight line in the center of the screen, as shown in Figure 3,28.If you want to expand the vertical display range, you can adjust the reference level soft key to adjust the normalized line to the top of the display part, as shown in Figure 3,29.

2. Remove the adapter and replace the adapter with a filter to display the filter characteristics, as shown in Figure 3.30 shown.

If necessary, adjust the [SPAN] key, and then you can see the complete filtering characteristics of the filter on the display.
—Press 【Marker】key to move the cursor to -3dB, then you can measure the 3dB bandwidth of the filter.
If you want to take a closer look at the filter characteristics, you can choose the ordinate scale of 1dB/grid.

Accessory Test Operation Guide

4.1 Near-field probes
Using a near-field probe with a receiver can directly measure the frequency and amplitude of the interference signal, which is very effective in finding electric and magnetic field interference. Compared with similar probes, the Baluelec near-field probe has high gain and small volume, and can perform quantitative measurements.

4.1.1 Use a near-field probe to find electromagnetic leakage in the chassis gap
Any shielded case has gaps, various windows and input/output lines, and electromagnetic waves are likely to come from These places leak out. The solution is: all the gaps must be blocked with conductive voltage strips, and the window Different light-transmitting shielding materials should be used for the mouth. All input/output lines must pass through filters and shielded enclosures external circuit connections. If the selection or installation of conductive voltage strips and filters is not suitable, or the light- transmitting screen of the window If the performance of the shielding material is not good, there will be electromagnetic leakage, and the near-field diagnostic probe can be used to check the leakage location and leakage. the size of.

Measurement methods

1. Device connection
   Connect the near-field probe to the spectrum input of the spectrum analyzer.

2. Parameter setting

1. Reset the instrument —Press [Preset] 2) Setting parameters
   —Press[FREQ]key to adjust the center frequency to the estimated detection frequency
   —Press[SPAN]key to set the sweep width to the widest first, so that the display will be a panoramic spectrum.
   Move the probe (as shown in the figure) at the place where the EUT needs to be inspected (such as gaps, ventilation windows, etc.).
   Adjust the center frequency to a relatively large spectral line, and use the frequency marker to observe the frequency and amplitude of the spectral line.

After seeing a relatively large interference signal, reduce the sweep width and IF bandwidth to observe the details of the spectral line part. If the measured signal is too small, then

• Press the [BW] key to reduce the IF bandwidth, and press the [Attenuator] key to reduce the attenuation You can also turn on the internal preamplifier, or use an external low noise amplifier to amplify the measured signal.
• Press[AMPT]key to adjust [reference level], and adjust the amplitude of the signal under test to a position convenient for observation. Observe while moving the probe. Find the relatively large radiation frequency and amplitude. It is also possible to use the maximum hold Function record signal line
• Press [Trace]key to select [Maximum Hold] function
• Press[Marker]key to move the cursor to the spectral line to be measured

4.1.2 Use a near-field probe to find the source of electromagnetic interference on the PCB
Electronic circuits are composed of many components (resistors, capacitors, inductors, transistors, integrated circuits, semiconductors
Switching devices and high-frequency clock processor chips, etc.) are connected by wires, cables and connectors. each element
Devices have their inherent characteristics, and some components can generate strong electromagnetic radiation.
Some cables are often bundled together, which creates a potential hazard for near-field coupling or crosstalk. wire
It can be equivalent to a dipole antenna and can act as a radiation antenna, thus becoming a part of the electromagnetic interference radiation source
It can also function as a receiving antenna and becomes an important part of the system that is sensitive to radiated emissions. use near field
The diagnostic probe can find out the components with large electric field radiation and the magnitude of the electromagnetic field radiation.
The measurement method is the same as 4.1.1.

The above are all relative measurements, and relative measurements can only qualitatively analyze the magnitude of the measured signal.
For example, the radiated emission (RE102) measurement of a certain military equipment exceeds the standard, and at 100MHz, the limit value is exceeded 10dB, in order to meet the requirements of the military standard, this product must be reinforced and improved.
The correct way to strengthen is to measure with a diagnostic probe first, and the signal exceeds the standard at 100MHz.
The magnitude value of the number, measure after reinforcement measures, compare the data of the two measurements, if the second measurement data
The value reduced by less than 10dB compared with the first measurement data indicates that the reinforcement measures are not enough. If the reduced value
If it is greater than 10dB, it may pass the military standard limit requirement. Because the change of the electromagnetic field strength in the near field and the change of the far field The rules are basically the same.

4.1.3 Quantitative testing (absolute value measurement) is possible with near-field probes
All TEMPEST electromagnetic field probes have been calibrated by nationally certified measurement units, and the corresponding
Probe calibration coefficient AF, with which the field strength quantitative test can be carried out, and the absolute
For the field strength value, such as the electrical field near the transmitter, substation, radio room, computer room, cabinet and inside the case, etc.
Places with strong magnetic radiation.
The calculation formula of electromagnetic field theory is as follows:
Electric field strength E(dBBμv/m)=V(dBBμv )+AF(dB/m)
Magnetic field strength H(dBBμA/m)= V(dBBμv )+AF(dBs/m)
Magnetic induction (magnetic flux density) B(dBpT) = H(dBÿA/m)+2dB= V(dBBμv )+AF(dBs/m) +2dB
In the formula: V(dBBμv ) —— measured value of spectrum analyzer
AF(dB/m)——electric field probe correction factor
AF(dBs/m)——Correction coefficient of magnetic field probe
Measuring with a diagnostic probe is different from the method of measuring according to the military standard. The diagnostic measurement is a near-field measurement, and the near-field measurement is a With a probe, the probe is in close proximity to the radiation source. The measurement according to the electromagnetic compatibility standard basically belongs to the far-field measurement, and the far-field measurement The amount is with an antenna. The military standard requires that the distance between the antenna and the device under test is 1m. In order to eliminate the environmental electromagnetic interference, the radiation emission Radiation measurements must be carried out in a shielded dark room.
Probe Measurement Error Analysis: There are many factors affecting near-field measurement

1. The magnetic component of the signal is coupled to the probe through magnetic induction, while the electrical component is coupled through capacitive onto the probe. Since the distributed capacitance is not fixed, the induced electric component also changes, so each measurement The repeatability is poor.
2. Influence of the probe: when th e probe is placed near the radiation source, due to the presence of the probe, the The capacitance of the source is increased, thereby changing the distribution of the current at the interaction point, thus changing the flux density of the source Spend. This can also lead to measurement errors.
3. The wave impedance in the near field changes and is particularly sensitive to the position of the probe.
4. The influence of the human body: when a person holds the probe, the electrical signal component can pass through the separation between the human body and the probe. The distributed capacitance is coupled to the probe, and the position of the person or the method of holding the probe is different, the distributed capacitance is also different. same.

During diagnostic measurement, keep the human body as far away from the probe and measurement cable as possible to eliminate the influence of the human body. Due to electromagnetic waves There is a problem with the direction of polarization, so the direction of the probe should be rotated during the measurement in order to measure the largest signal. For phase For measurement, the conditions before and after the measurement should be as similar as possible. As long as you pay attention to the measurement method, you can reduce the measurement error.
Due to the many measurement errors caused by near-field measurement, how to equate the near-field measurement data to the far-field
There is no ready-made theoretical calculation formula. Because the size of the shielded darkroom is different, the electromagnetic wave reflection is different, The test distance is different, so it is difficult to derive a theoretical calculation formula for the equivalent far and near field. However, there are conditions Some units can conduct actual measurements according to the specific conditions of their own laboratories to find out a rule. In general, near The electromagnetic field strength measured in the far field is much stronger than that measured in the far field, and it increases with frequency The difference also decreases linearly. In this way, it can be pre-estimated whether the device under test can pass the military standard requirements.

4.2 Current Sense Probes and Current Injection Probes
Most of the interference signals are related to the presence of interference currents in wires and cables, which can wait for
The effect is a loop antenna and a dipole antenna, which can both transmit and receive signals. In EMC measurements,
Measuring the performance of the transmitted signal on the cable of the equipment is called conducted emission measurement; applying a certain intensity to the cable of the equipment
To assess the anti-interference ability of the equipment with a high-degree signal is called conduction sensitivity measurement. Whether measuring interference on the cable
Whether to inject disturbances into the cable, a coupling device is required, which is usually called a current probe (or called a current caliper). Current probes can be classified into current sense probes and current injection probes. Current sense probe Used to measure conducted emissions, to measure interference on conductors and cables; current injection probes are used to measure conducted susceptibility Quantity, that is, the technology of injecting strong interference signals into the cable, referred to as BCI (Buik Current Injection). When using a current probe, the probe does not touch the wire, and generally does not change the normal state of the circuit under test. State of working or normal arrangement.

4.2.1. Measuring interference on power and signal lines with a current detection probe
Connect the current detection probe to the input terminal of the spectrum analyzer, and snap the current detection probe to the power line under test, In this way, the electromagnetic interference on the power line can be measured, and it can also be stuck on  the signal line to measure the interference on the signal line.
As shown below.

4.2.2 Measuring the Conducted Sensitivity of the DUT with a Current Injection Probe

Measurement methods:
Clamp the current injection probe to the signal cable or power line under test, and pass the output signal of the signal source through the The power amplifier is amplified and added to the current injection probe, and the current detection probe is used to monitor the injection into the wire Signal current size. In this way, the purpose of sensitivity measurement can be achieved. As shown in Figure 4.6.

4.3. Measuring common-mode and differential-mode signals with a common- differential mode separator
The traditional conduction measurement can only measure the total amount of conduction interference of the device under test from the L/N detection terminal of the LISN.
The total amount of interference includes common-mode components and differential-mode components. I don’t know how much each of the common- differential mode components is. This gives EMI It is difficult for design and modification engineers to choose which filter to use.
With the common and differential mode separation function in the EA3040B integrated analyzer, the common mode can be separated from the total interference Component and differential mode component, which is convenient for designers and rectification personnel to carry out interference analysis and directional processing.
The specific operation of the common-differential mode separation function is explained below with specific examples.

1. Device connection
   Connect the equipment according to the GJB151A/152A conducted emission measurement in section 6.3. After the actual connection as shown in the figure 21.

2. Parameter setting
   —PressÿModeÿkey
   —Press [EMI Receiver] — by [Standard] – Press [Conduct] —Press [CE102-1]

3. Total interference measurement
   After the parameters are set, connect the detection terminal “L Output/N Output” of the front panel LISN to the frequency spectrum After the scan is stable, observe whether the curve exceeds the standard limit, and adjust the frequency to exceed the standard limit.
   On the target spectral line, at this time, the total amount of interference exceeds the standard by 22dB at 131kHz. As shown in Figure 4.8.

Editing and saving of instruments

5.1 Limit line editing of the instrument
5.1.1 Limit lines of the instrument
The measurement limit lines of built-in standards cannot be edited, and the measurement of custom standards needs to define limit lines. limit line knitting After the editing is completed, it can be saved to the device, and it can be browsed, edited and deleted when it is started next time.
The picture below is a blank page

5.1.2 Limit line parameters and operation steps
[Page number] The limit line list displays 12 items per page, and will be displayed in pages after more than 12 items
[Name] The name of the limit line, input from the software disk, after the cursor switches to the name parameter, click on the front panel
[Enter] key can activate/deactivate the software disk
ÿLimitÿ Limit line type definition, upper limit/lower limit
[X coordinate] Linear/logarithmic, currently only supports X coordinate logarithmic unit only supports dBuV unit
[Note] Custom description, the input method is the same as the name edit line operation
After the instrument is turned on and the system enters the EMI receiver, click [Meas Setup] to enter the limit line editing page,
Specifically: [Meas Setup] → [New], start creating limit lines
The left side is the limit line parameter editing part, and the right side is the shortcut switch and function menu
[Name] Quickly locate the cursor to the name parameter column
[Value] Quickly position the cursor to the first frequency
[Add]Create a new frequency, amplitude line and position
[Insert]When the cursor is in the frequency/amplitude row, perform an insertion before it, and if it is not there, perform an add operation
[Delete] Delete frequency/amplitude line
[Give up]Cancel creation/editing and return to limit line list page
[Save] Save the creation/editing and return to the limit line list page

The operation of editing a page is exactly the same as that of creating a page. After editing, click [Save] to return to the list page.

5.1.3 Creation and use of limit lines
You can edit and use limit lines yourself for quick measurements, also for list sweeps.
[Meas Setup] menu contains all the operations of the limit line, the menu functions are as followsThe left part is the limit line list that has been created, and the parameters included in the limit line list are
[Name]Limit line name
[Limit] Limit line type, including Upper (upper limit line) and Lower (lower limit line), upper limit line table
Indicates that when the detection result exceeds the limit line, it is qualitatively exceeded, and the lower limit line is just the opposite, lower than the lower limit line out of bounds
[X coordinate] Horizontal axis display mode, Log means logarithmic display, Line means linear display
[Unit]dBuV
[X axis]Display the absolute frequency value
[Y axis]display relative frequency value
[Note] Remarks
Limit line operations mainly include: browse/refresh, create, edit, delete and copy operations.

5.1.3.1 Create limit lines
[Meas Setup]j→[New], enter the interface for creating limit linesSet limit line name
Input the limit line name through the soft keyboard, click [Name] to pop up the soft keyboardThe soft keyboard contains English letters and common symbols, which can be moved by the pulse knob and the up and down keys, [Enter] to confirm
When inputting numbers, it can also be input through the number keys on the panel, and the [Cancel] and [OK] keys close the soft key.
keyboard.
Add extreme frequency points: Click [Add]/[Insert], the limit line frequency point list will automatically add a line, pulse
The knob moves to the frequency or limit table that needs to be modified, input and modify through the number keys on the panel.
After editing, click [Save], and the system will automatically return to the limit line list interface.

5.1.3.2 Enabling limit lines
[Meas Setup]Enter the limit line list home pageUse the pulse knob to switch between enable and trace form, enable or cancel by [Enter] key, trace selection
The selection range is from 1 to 3, and the corresponding trace is selected according to the actual set parameters. After reset, the system automatically cancels all There are limit lines.

5.2 Instrument Compensation Factor Editing
Compensation factors can be edited for testing accessories such as LISN, probe, antenna, limiter, attenuator, amplifier, etc.
Corresponding compensation is made for the insertion loss and frequency response to ensure accurate and reliable test results.
Operation steps: [Meas]→[Compensation], enter the compensation factor interface

5.2.1 Creating Compensation Factors
Operation steps: [Meas]→[Compensation]→[New], after entering the page, you can set the compensation name, add Frequency list, set frequency and amplitudeAfter the creation is complete, click [Save]

5.2.2 Load compensation factor
[Meas]→[Compensation], enter the compensation list interface, use the up and down keys to select the compensation name, press [Enter] key to enable compensation

Note: Only one of them can be selected in the compensation list at a time.

5.3 Save operation
The interface saving of the instrument is divided into two types: report export under the EMI receiver system and interface saving under other methods live.
Report export:
Under the EMI receiver system, stop scanning, click [Meas], click [Report], and select [Export] After that, the report can be saved to flash memory. There are two saving formats, .png and .html. When viewing the two Put the files in the same path, just open the file with the suffix html.
The test report style is as followsThe test report includes measurement spectrum and outlier data information. The exceeding standard point data gives the current exceeding standard frequency point limit value, the measured value and the difference between the measured value and the limit value.
Interface save:
In the spectrum analyzer mode, the interface is saved in the form of screenshots, after [System], click [Save] [Storage], click [Screenshot], and click [Save to Flash]. The save format is only .png.

Precautions for using the instrument

When using the instrument, pay attention to electricity safety.
After the instrument is turned on, it needs to warm up for 25 minutes. After the system is stable, start measuring.
When the instrument is conducting a conduction test, when using it with an external LISN, pay attention to the order of the test steps, note Pay attention to electricity safety.
When using the instrument, pay attention to the issue of safety grounding, which requires good grounding.
Do not place the instrument in a place exposed to sunlight for a long time after use.
When the instrument is not in use, please disconnect the power supply.

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