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Getting Started

3.2 Taking Measurements

To perform accurate measurements, the following is a minimum list of things you should know about the signal that you

wish to measure.

Signal Frequency

The center frequency of the carrier must be known to allow sensor frequency response compensation.

Modulation Bandwidth

If the signal is modulated, know the type of modulation and its bandwidth. Note that power sensors respond only to

the amplitude modulation component of the modulation, and constant envelope modulation types such as FM can be

considered a CW carrier for power measurement purposes.

3.2.1 Continuous Mode

Continuous mode is best for measuring repetitive signals. Since this mode performs a continuous measurement, it does

not differentiate between the times a pulsed or periodic signal is off, and the times it is on. If you wish to make

measurements that are synchronous with a period of a waveform, consider using Pulse mode instead.

Continuous mode is best for the following types of measurement:

• Moderate signal level (above -40 dBm for Peak sensors and -60 dBm for CW sensors).

• Signal that is CW or continuously modulated with a modulation bandwidth that is less than the VBW of the sensor

in use.

• Signal modulation may be periodic, but only non-synchronous measurements are needed (overall average and peak

power).

• Noise-like digitally modulated signals such as CDMA and OFDM when only average measurements are needed.

The measured result is the average power of the signal. Since the graphic display would basically just show a straight

line, measurements in Continuous mode are best viewed using the Text Display mode. Figure

3.1

shows a two-channel

measurement displaying an average, minimum, and maximum power in Continuous mode.

Figure 3.1

Average

Содержание RFM3000 Series

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Страница 2: ...lso accompanied by a maximum voltage of the circuit to be tested which defines the voltage impulses expected and required insulation clearances These categories are Category I CAT I Measurement instruments whose measurement inputs are not intended to be connected to the mains supply The voltages in the environment are typically derived from a limited energy trans former or a battery Category II CA...

Страница 3: ...or flammable atmosphere Do not operate the instrument in the presence of flammable gases or vapors fumes or finely divided particulates The instrument is designed to be used in office type indoor environments Do not operate the instrument In the presence of noxious corrosive or flammable fumes gases vapors chemicals or finely divided particulates In relative humidity conditions outside the instrum...

Страница 4: ... the covers are removed To avoid injuries always disconnect the power cord from the instrument disconnect all other connections for example test leads computer interface cables etc discharge all circuits and verify there are no hazardous voltages present on any conductors by measurements with a properly operating voltage sensing device before touching any internal parts Verify the voltage sensing ...

Страница 5: ...move the instrument when a probe is connected to a circuit being tested Compliance Statements Disposal of Old Electrical Electronic Equipment Applicable in the European Union and other European countries with separate collection systems This product is subject to Directive 2002 96 EC of the European Parliament and the Council of the European Union on waste electrical and electronic equipment WEEE ...

Страница 6: ...serious injury indicates a hazardous situation which if not avoided will result in minor or moderate injury Refer to the text near the symbol Electric Shock hazard Alternating current AC Chassis ground Earth ground This is the In position of the power switch when instrument is ON This is the Out position of the power switch when instrument is OFF is used to address practices not related to physica...

Страница 7: ... Drop Down Menus 26 4 3 Menu Reference 27 4 3 1 Main Menu 27 4 3 2 Measure 28 4 3 3 Display 29 4 3 4 Stat Mode 29 4 3 5 Channel 30 4 3 6 Channel Settings 31 4 3 7 Time 34 4 3 8 Trigger 34 4 3 9 Pulse Def 36 4 3 10 CH Pulse Def 36 4 3 11 Favorites 38 4 3 12 System 38 5 Application Notes 42 5 1 Introduction to Pulse Measurements 42 5 1 1 Measurement Fundamentals 42 5 1 2 Diode Detection 44 5 1 3 Pul...

Страница 8: ...8 6 Maintenance 55 6 1 Safety 55 6 2 Cleaning 55 6 3 Inspection 55 6 4 Lithium Battery 56 6 5 Software Upgrade 56 7 Service Information 57 8 LIMITED THREE YEAR WARRANTY 58 ...

Страница 9: ...on provides instructions for unpacking the instrument setting it up for operation connecting power and signal cables and initial power up Section 3 Getting Started describes the controls and indicators and the initialization of operating parameters Several practice exercises are provided to familiarize yourself with essential setup and control procedures Section 4 Operation describes the display m...

Страница 10: ... to four RFP Series Sensors with industry leading performance and capabilities either independently or for synchronized multi channel measurements of CW modulated and pulsed signals Providing the ultimate flexibility the RFM3000 sensors can be disconnected and independently used as standalone instruments 1 3 Features Compatible with B K Precision s RFP3000 Series USB RF Power Sensors Capture displ...

Страница 11: ... 4 Front Panel Refer to table 1 1 for a description of each of the illustrated items The function and operation of all controls indicators and connectors are the same on the standard and optional models Figure 1 1 Front Panel ...

Страница 12: ...hannels screen menus status messages text reports and help screens 5 Favorites key This function is not fully implemented at this time Enables the user to setup a customized menu to allow grouping frequently used menu items into one convenient menu 6 Store image key saves a screen image of the meter to local storage The images can be copied to an external USB storage device 7 Used to assist naviga...

Страница 13: ...1 5 Rear Panel Refer to table 1 2 for a description of each of the illustrated items The function and operation of all controls indicators and connectors are the same on the standard and optional models Figure 1 2 Rear Panel ...

Страница 14: ...remote control and firmware updates Allows DHCP or fixed IP Sub net setting mode LAN parameters can be configured through the menu 7 HDMI HDMI receptacle for connecting an external monitor to mirror front panel display The image resolution will be 800 x 480 and will be stretched to fit the external full display size 8 AC Line Input A multi function power input module is used to house the AC line i...

Страница 15: ...xt Display mode of the instrument provides a table view of measured parameters Parameters depend on the Measure mode selected See Section Menu Referencefor more information on the display format Figure 1 3 Display Figure 1 4 Display Hidden Menu ...

Страница 16: ...play This area will show a plot when in Graph Display mode or a table of parameters when in Text Display mode for the measurement mode selected 5 Menu Bar Select to show and to hide the on screen menus 6 Menu Parth Used to navigate the menu structure Shows the menu that will be displayed when selected 7 Current Menu Home Displays the name of the current menu and provides a home shortcut to the top...

Страница 17: ... equipped with a switching power supply that provides automatic operation from a line voltage input within The supply has a universal AC input that accepts line voltage input within Voltage 100 240 VAC 10 Frequency 43 to 63 Hz Input Power 70 VA MAX Before connecting the instrument to the power source make certain that a 1 0 ampere time delay fuse type T is installed in the fuse holder on the rear ...

Страница 18: ...to the bus using the rear panel GPIB connector and appropriate cable For Ethernet control connect to the rear panel LAN connector In most cases it will be necessary to configure the interface using the System I O Config menu 2 4 Preliminary Check The preliminary check verifies that the instrument is operational and has the correct software installed It should be performed before the instrument is ...

Страница 19: ...s the select key to bring up the on screen menu From the Main menu use the touch screen or the navigation keys on the front panel to browse to System Reports Configuration and select Show A display similar to figure 2 2 will appear Figure 2 2 Configuration Report Display ...

Страница 20: ...pdating After the last dialog the main screen will be on the display When selecting a sensor for an exercise or a measurement be sure you know the power range of the sensor Operation beyond the specified upper power limit may result in a permanent change of characteristics or burnout 4 Connect the sensor USB cable to the Channel 1 input on the front or rear of the instrument When the sensor is con...

Страница 21: ...aging 8 Units dBm Video BW HIGH Peak Hold OFF dB Offset 0 dB Parameters Related to the Time Menu Timebase 100 uS div Position 5 0 divisions Trigger Delay 0 0 uS Parameters Related to the Trigger Menu Holdoff 0 uS Trigger Mode AUTOPKPK Trigger Slope Positive Trigger Source CH1 Parameters Related to the Markers Menu Marker 1 300 uS Marker 2 300 uS Parameters Related to the Pulse Def CH Pulse Def Men...

Страница 22: ...d or periodic signal is off and the times it is on If you wish to make measurements that are synchronous with a period of a waveform consider using Pulse mode instead Continuous mode is best for the following types of measurement Moderate signal level above 40 dBm for Peak sensors and 60 dBm for CW sensors Signal that is CW or continuously modulated with a modulation bandwidth that is less than th...

Страница 23: ...terest for detailed power analysis The instrument can display power at each marker as well as average minimum and maximum power in the region between the two markers This is very useful for examining the power during a TDMA or GSM burst when only the modulated portion in the center region of a timeslot is of interest By adjusting trigger delay and other parameters it is possible to measure the pow...

Страница 24: ...cur Analysis of millions of data points gathered during a sustained measurement of several seconds or more can yield the statistical probabilities of each signal level with a high degree of confidence Statistical mode is best forthe following types of measurements Moderate signal level above about 40 dBm except when modulation is off Noise like digitally modulated signals such as CDMA and all its ...

Страница 25: ...ence of the peaks but the CCDF clearly shows this information In Figure 3 8 assume a full length run of one hour plus has been made and the CCDF is analyzed At 0 is the maximum peak power that occurred during the entire run At 1 is the power level that was exceeded only 1 of the time during the entire run Note that this analysis does not depend upon any particular test signal or upon synchronizati...

Страница 26: ...icated for mode dependency Menus with more selections than what fits on the display can be scrolled with the touch screen or front panel buttons 4 2 Parameter Date Entry and Selection The RFM3000 s parameters can be changed in various ways depending on the type of parameter being addressed 4 2 1 Numerical Data Entry Drop Down Menus Numerical data can be incremented decremented by selecting the and...

Страница 27: ... in figure 4 2 is the top most menu level from which all other menus originate Measure Display Stat Mode Channel Time Trigger Markers Pulse Def Favorites System When navigating any submenu the icon will appear to the right of the submenu name Press the icon to return to the main menu Figure 4 2 Main Menu ...

Страница 28: ...de Only and will stop once the measurement criteria averaging has been satisfied Meas Clear Stat Capture Selecting Execute clears display traces data buffers and clears averaging filters to empty In Statistical Measure mode the menu item is replaced with Stat Capture and selecting Reset clears the acquired sample population Single Sweep Only available in Pulse mode Select to start a single measure...

Страница 29: ...xcursions or envelope of the signal will be illuminated for each horizontal trace pixel Envelope display is only available for Peak Power sensors Key Beep Enable disable the audible key beep Figure 4 4 Display Menu 4 3 4 Stat Mode To enter the Stat Mode menu press the icon then select the Stat Mode menu Cursor Pct Cur Pow Ref Sets the CCDF cursor to the desired probability When Cursor mode is set ...

Страница 30: ... Action Select the action to take when either the terminal count is reached or terminal time has elapsed Selecting Decimate will divide all sample bins by 2 and continue The total sample count will be halved each time a decimation occurs Selecting Restart clears the statistical sample population and starts a new one Selecting Stop will stop accumulating samples and hold the result 4 3 5 Channel To...

Страница 31: ... ments Trace averaging is a continuous process in which the measurement points from each sweep are weighted multiplied by an appropriate factor and averaged into the existing trace data points The most recent data will always have the greatest effect on the trace waveform and older measurements will be decayed at a rate determined by the averaging setting and trigger rate This averaging technique ...

Страница 32: ...r specified integration time to be entered for use Auto uses a variable amount of filtering which is set automatically by the power me ter based on the current signal level to a value that gives a good compromise between measurement noise and settling time at most levels Figure 4 10 Channel Setttings Filter Time Available in Continuous mode only Sets the length of the integration filter The filter...

Страница 33: ...tenuators or amplifiers in the RF signal path ahead of the power sensor Zero Performs a zero offset null adjustment The sensor does not need to be connected to any calibrator for zeroing This action removes the effect of small residual power off sets and should be performed prior to low level measurements The procedure is often performed in system There should be no RF signal applied to the sensor...

Страница 34: ...igger To enter the Trigger menu press the icon then select the Trigger tab Trigger Holdoff Set the trigger holdoff time Trigger holdoff is used to disable the trigger for a spec ified amount of time after each trigger event The holdoff time starts immediately after each valid trigger edge and will not permit any new triggers until the time has expired When the holdoff time is up the trigger re arm...

Страница 35: ...ronization with a pulse signal of varying level The Freerun mode forces unsynchronized traces at a high rate to assist in locating the signal Trigger Source Set the trigger source used for synchronizing data acquisition The CH settings use the signal from the associated sensor Ext setting uses the signal applied to the rear panel TRIG IN connector The trigger source can be any of the resource chan...

Страница 36: ...lay limits is entered the marker will be placed at the first or last time position as appropriate ΔTime Displays the result of Marker 2 1 in seconds This item is read only Figure 4 15 Marker Setttings 4 3 9 Pulse Def To enter the Pulse Def menu press the icon then select the Pusle Def tab CH Pulse Def Select the channel to be configured Figure 4 16 Pulse Def Menu 4 3 10 CH Pulse Def To enter the C...

Страница 37: ... thresholds are computed as voltage percentages If Watts are selected they are computed as power percentages units setting Figure 4 17 CH Pulse Def Menu Many pulse measurements call for 10 to 90 voltage which equates to 1 to 81 power for risetime and falltime measurements and measure pulse widths from the half power 3 dB 50 power or 71 voltage points The Pulse Units setting is independent of the c...

Страница 38: ...tem To enter the System menu press the icon then select the System tab The System menu displays the available system level features and functionality Seonsr Data I O Config Calibration Exit Reports Update Software Figure 4 18 System Menu cm Sensor Data To enter the Sensor Data menu press the icon then select the System Sensor Data tab Press Show to display information about the selected sensor in ...

Страница 39: ...ig LAN tab DHCP AutoIP Set the state of DHCP AutoIP system for the Ethernet port If DHCP AutoIP is enabled On the instrument will attempt to obtain its IP Address and Subnet Mask a DHCP dynamic host configuration protocol server on the net work If no DHCP server is found the instrument will select its own IP Address and Subnet Mask values using the AutoIP protocol If DHCP AutoIP is disabled Off th...

Страница 40: ...or Exit To enter the Exit menu press the icon then select the System Exit tab Exit to Desktop Exits the RFM3000 Power Meter Main application to access the OS Desktop Shut Down Shuts down power to the PMX40 putting the meter in standby mode and is the same as pressing the ON Standby button on the front panel Figure 4 24 Exit Reports To enter the Reports menu press the icon then select the System Re...

Страница 41: ...n then select the System tab Update Software Select Go to search the connected USB drive for the tar software update file and up date or re install the version found If no valid file is found the dialog in figure 4 27 appears Figure 4 26 Update Software Figure 4 27 Update Error ...

Страница 42: ...pond to the voltage of the signal With careful calibration accurate measurements can be obtained over a wide range of input power levels Modulated Carrier Power The average power of a modulated carrier which has varying amplitude can be measured accurately by a CW type power meter with a thermoelectric detector but the lack of sensitivity will limit the range Diode detectors can be used at low pow...

Страница 43: ...le these samples can be averaged to yield average power without restriction to the diode square law region If the signal is repetitive the signal envelope can be reconstructed using an internal or external trigger The envelope can be analyzed to obtain waveshape parameters including pulse width duty cycle overshoot rise time fall time and droop In addition to time domain measurements and simple av...

Страница 44: ... 1 where 𝑖 𝑑𝑖𝑜𝑑𝑒𝑐𝑢𝑟𝑟𝑒𝑛𝑡 𝑣 𝑛𝑒𝑡𝑣𝑜𝑙𝑡𝑎𝑔𝑒𝑎𝑐𝑟𝑜𝑠𝑠𝑡ℎ𝑒𝑑𝑖𝑜𝑑𝑒 𝐼𝑠 𝑠𝑎𝑡𝑢𝑟𝑎𝑡𝑖𝑜𝑛𝑐𝑢𝑟𝑟𝑒𝑛𝑡 𝛼 𝑐𝑜𝑛𝑠𝑡𝑎𝑛𝑡 An ideal diode response curve is plotted in figure 5 3 Figure 5 3 Ideal Diode Response The curve indicates that for low microwave input levels Region A the single diode detector output is proportional to the square of the input power For high input signal levels Region C the output is linearly proportional to the in...

Страница 45: ...ion C figure 5 3 the detector responds to the vector sum of the signal and harmonics Depending on the relative amplitude and phase relationships between the harmonics and the fundamental measurement accuracy may be significantly degraded Errors caused by even order harmonics can be reduced by using balanced diode detectors for the power sensor This design responds to the peak to peak amplitude of ...

Страница 46: ...0 text mode display of automatic measurement results 5 1 4 Standard IEEE Pulse The key terms defined by the IEEE standard are abstracted and summarized below These terms are referenced to the standard pulse illustrated infigure 5 4 Figure 5 4 Stanard IEEE Pulse Note IEEE Std 194 1977 Standard Pulse Terms and Definitions has been superseded by IEEE Std 181 2003 Many of the terms used below have bee...

Страница 47: ...iddle of a pulse at a specified percentage normally 50 of pulse magnitude Table 5 1 Pule Terms 5 1 5 Automatic Measurements The RFM3000 automatically analyzes the waveform data in the buffers and calculates key waveform parameters The calculated values are displayed in text mode when you press the TEXT GRAPH system key 5 1 6 Automatic Measurement Criteria Automatic measurements are made on repetit...

Страница 48: ...s of a repetitive signal that take place in one Frequency second Duty C Duty Cycle The ratio of the pulse on time to off time Offtime Off time The time a repeti tive pulse is off equal to the pulse period minus the pulse width Peak Peak Power The maximum power level of the captured waveform Pulse Pulse Power The average power level across the pulse width defined by the intersection of the pulse ri...

Страница 49: ...of the maximum and minimum sample amplitudes 4 The processor locates each crossing of the Transition Threshold 5 Starting at the left edge of the screen the processor classifies each Transition threshold crossing according to whether it is positive going or negative going Because the signal is repetitive only three transitions are needed to classify the waveform as follows Type Sequence Descriptio...

Страница 50: ...e process uses the samples that lie between the edge of the screen and the transition threshold see figure 5 6 For a level to be designated the top amplitude the number of crossings of that level must be at least 1 16 the number of pixels in the pulse width otherwise the peak value is designated the top amplitude Figure 5 6 Time Interpolation 9 The process establishes the proximal mesial and dista...

Страница 51: ...n the proximal and distal crossings The fall time is defined as the time between the distal and proximal crossings If no samples lie between the proximal and distal values for either edge rise or fall the risetime for that edge is set to 0 seconds 12 The processor calculates the output values according to the following definitions a b c d e f g h i j k l m n Pulse Width Rise time Fall time Period ...

Страница 52: ...n a finite time interval the endpoints are handled separately to avoid spreading the interval by one half pixel at each end of the interval see figure For the interval in figure the average power is given by 𝑃𝑎𝑣𝑔 1 2 𝑃0 𝑃𝑛 1 𝑛 1 𝑛 1 𝑛 1 𝑃𝑛 Figure 5 7 Sampling Interval 14 The processor calculates the delay between the two measurement channels The time reference for each channel is established by th...

Страница 53: ...screen In the Statistical mode the following five automatic measurements are displayed in the PMX40 Text display for both input channels and both trigger channels The Text column lists the abbreviated forms that appear on the display screen TEXT TERM DEFINITION Avg Average Power The unweighted average of all linear power samples occurring since acqui sition started Peak Peak Power The highest powe...

Страница 54: ...CCDF at the refer ence power level specified by the user Cursor Mode Percent The probability in percent set by the user to define the measurement point on the normalized CCDF for power level in dBr Total Time The total time in Hours Minutes Seconds that the data acquisition has been running Points The total number of data samples in MSa that has been acquired for each channel in the current run Ta...

Страница 55: ...indow cleaner or a mild detergent and water solution Note When cleaning the instrument do not allow cleaning fluid to enter the fan intake and exhaust vents Avoid using chemical cleaning agents that can damage painted or plastic surfaces 6 3 Inspection If the RFM3000 malfunctions perform a visual inspection of the instrument Inspect for signs of damage caused by excessive shock vibration or overhe...

Страница 56: ...K Precision Model RFM3000 Application Software The Application Software will be updated from time to time to correct errors and add new features Users can upgrade their software by downloading it from the BK Precision webpage bkprecision com Copy the upgrade file s into the root directory on a USB drive and plug the drive into one of the instrument s USB ports front or rear From the RFM3000 applic...

Страница 57: ... probes connectors and accessories that you are using with the device Customers not on an open account must include payment in the form of a money order or credit card For the most current repair charges please refer to the service and support section on our website Return all merchandise to B K Precision Corp with prepaid shipping The flat rate repair charge for Non Warranty Service does not incl...

Страница 58: ... via our website www bk precision com Exclusions This warranty does not apply in the event of misuse or abuse of the product or as a result of unauthorized alterations or repairs The warranty is void if the serial number is altered defaced or removed B K Precision Corp shall not be liable for any consequential damages including without limitation damages resulting from loss of use Some states do n...

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