Ladybug USB PowerSensor+ LB A Series User manual

LBXXXA Series USB PowerSensor+™
Product Manual PMA (Power Meter Application)
Revision: 08/02/11 - 1 -
Product Manual for the
POWER METER APPLICATION
MODELS LB478A/479A/480A/559A/579A/589A/679A/680A

LBXXXA Series USB PowerSensor+™
Product Manual PMA (Power Meter Application)
Revision: 08/02/11 - 2 -
Table of Contents
TABLE OF CONTENTS ..............................................................................................................................................................................................2
NOTICES....................................................................................................................................................................................................................3
1. GENERAL INFORMATION ....................................................................................................................................................................................4
INTRODUCTION .........................................................................................................................................................................................................4
DESCRIPTION ...........................................................................................................................................................................................................4
USB CONSIDERATIONS.............................................................................................................................................................................................4
More information related to USB.........................................................................................................................................................................5
How to identify the type of USB port...................................................................................................................................................................5
APPLICATIONS..........................................................................................................................................................................................................6
ACCESSORIES SUPPLIED...........................................................................................................................................................................................6
SPECIFICATIONS.......................................................................................................................................................................................................7
OPTIONS..................................................................................................................................................................................................................8
WARRANTY ..............................................................................................................................................................................................................8
SERVICE ..................................................................................................................................................................................................................8
CALIBRATION CYCLE.................................................................................................................................................................................................8
CONTACT INFORMATION............................................................................................................................................................................................8
2. INSTALLATION......................................................................................................................................................................................................9
INITIAL INSPECTION...................................................................................................................................................................................................9
SUPPORT CONTACT INFORMATION.............................................................................................................................................................................9
OPERATING SYSTEM AND COMPUTER REQUIREMENTS ................................................................................................................................................9
INSTALLATION PROCEDURE .......................................................................................................................................................................................9
Install the Software.............................................................................................................................................................................................9
3. BASIC OPERATING INSTRUCTIONS –GETTING STARTED ............................................................................................................................10
OPERATING PRECAUTIONS ......................................................................................................................................................................................10
PROGRAM START UP..............................................................................................................................................................................................10
CONFIGURING THE SENSOR.....................................................................................................................................................................................11
Measurement Update Rate...............................................................................................................................................................................11
Addressing the Sensor .....................................................................................................................................................................................11
MAKING BASIC MEASUREMENTS ..............................................................................................................................................................................12
Zeroing and Reference Power Calibration........................................................................................................................................................12
Setting the Center Frequency...........................................................................................................................................................................12
Display Preferences and Measurement Units...................................................................................................................................................13
Measurement Resolution..................................................................................................................................................................................14
Instrument Preset.............................................................................................................................................................................................14
Making an Average Power (CW) Measurement................................................................................................................................................15
Making a Pulse Power Measurement ...............................................................................................................................................................16
Alternate Pulse Measurement using Duty Cycle...............................................................................................................................................17
4. DETAILED OPERATING INSTRUCTIONS...........................................................................................................................................................19
MEASUREMENT OVERVIEW AND EXAMPLES ..............................................................................................................................................................19
The Power Meter Application............................................................................................................................................................................19
The Pulse Profiling Application.........................................................................................................................................................................19
Pulse Measurement Criteria (LB4XXA models only).........................................................................................................................................20
Pulse Peak Criteria (LB4XXA models only) ......................................................................................................................................................21
Measurement Example: OFDM Pilot Tone (LB4XXA models only) ...................................................................................................................22
Measurement Example: GSM (LB4XXA models only) ......................................................................................................................................25
GUI FUNCTIONS .....................................................................................................................................................................................................26
The Menu Bar...................................................................................................................................................................................................26
The Toolbar......................................................................................................................................................................................................27
Averaging.........................................................................................................................................................................................................29
Extended Averaging.........................................................................................................................................................................................29
Max Hold..........................................................................................................................................................................................................29
Anti-alias Control..............................................................................................................................................................................................30
Offset Correction..............................................................................................................................................................................................31
Making a Relative Power Measurement............................................................................................................................................................32
Frequency Response Correction......................................................................................................................................................................33
Impedance Matching........................................................................................................................................................................................34
Triggering.........................................................................................................................................................................................................35
Recorder ..........................................................................................................................................................................................................37
Data Logging....................................................................................................................................................................................................38
Limits Pass/Fail................................................................................................................................................................................................40
MEASUREMENT ACCURACY .....................................................................................................................................................................................42

LBXXXA Series USB PowerSensor+™
Product Manual PMA (Power Meter Application)
Revision: 08/02/11 - 3 -
Sensor Technology...........................................................................................................................................................................................43
Functional Block Diagram.................................................................................................................................................................................44
5. ERROR MESSAGES ...........................................................................................................................................................................................45
6. ERRATA AND USER UPDATES –BY DATE.......................................................................................................................................................45
REV DATE:01/07/08...............................................................................................................................................................................................45
REV DATE:03/24/08...............................................................................................................................................................................................45
REV DATE:04/15/08...............................................................................................................................................................................................45
REV DATE:06/16/08...............................................................................................................................................................................................45
REV DATE:08/19/08...............................................................................................................................................................................................45
REV DATE:11/20/08...............................................................................................................................................................................................45
REV DATE:02/06/09...............................................................................................................................................................................................45
REV DATE:02/24/09...............................................................................................................................................................................................45
REV DATE:03/27/09...............................................................................................................................................................................................45
REV DATE:04/09/09...............................................................................................................................................................................................46
NOTICES
© 2007 - 2011 LadyBug Technologies LLC
This document contains information which is copyright protected. Do not duplicate without permission or as allowed by
copyright laws.
SAFETY
A WARNING indicates a potential hazard that could completely damage the product. Do not continue until you fully
understand the meaning.
A CAUTION indicates a potential hazard that could partially damage the product. Do not continue until you fully
understand the meaning.
A NOTE provides additional pertinent information related to the operation of the product.
CONFORMITY
WEEE Compliant
RoHS Compliant
USB 2.0 Compliant
DISCLAIMER
The information contained in this document is subject to change without notice. There is no guarantee as to the
accuracy of the material presented or its application. Any errors of commission or omission will be corrected in
subsequent revisions or made available by errata.
WARRANTY
See the warranty section of this document for details.
DOCUMENT NUMBER
Not Assigned (Reference LBXXXA Product Manual for the Power Meter Application).

LBXXXA Series USB PowerSensor+™
Product Manual PMA (Power Meter Application)
Revision: 08/02/11 - 4 -
1. General Information
Introduction
This manual provides information about the installation and operation of the LB478A/479A/480A/LB679A/LB680A and
LB559A/579A/589A model USB power sensors when using the Power Meter Application software. The LB4XXA
series (reference to models LB478A/79A/80A and LB679A/80A) of sensors make CW and pulse measurements. The
LB5XXA series of microwave sensors make average - True RMS - (CW or modulated) measurements only. (The
LB480A/LB680A sensors are also capable of making pulse profile measurements –refer to the Pulse Profile
Application Quick Start Guide and Product Manual for the Pulse Profiling Application). This manual also contains
information regarding product features and support, specifications, compatibility, and some measurement examples.
Refer to the product Programming Guide for programming information. The Errata and User Update section at the end
of this document reflects recent changes in product development.
Description
The LBXXXA Series USB Power Sensor features a highly compact power sensor body that connects directly to a
desktop or laptop computer using a standard USB port and standard USB cable(s). A separate power meter is not
required. The LBXXXA Series USB Power Sensors convert RF and microwave power into digital data at the point of
measurement. The companion Power Meter Application software provides a front panel display, or Graphical User
Interface (GUI), that allows the user to make typical CW and pulse (modulation) measurements. This application is the
primary subject of this document. A programmatic interface is also supplied with the product.
Sensor zeroing and meter reference calibration are not required. This reduces setup time and simplifies programming.
The unit features optional source Trigger IN/OUT or Recorder OUT connectors in addition to a variety of RF input
connectors. Please refer to the Options section of this document for a complete listing of product options to include
extended performance and support.
PowerSensor+™ products address key aspects of general purpose scalar measurements as well as CW, pulse, and
other modulated power measurements. PowerSensor+™ products offer benefits in overall cost, accuracy,
measurement speed, flexibility and test development time.
SPECIAL NOTE: The RF input connector is field replaceable if the connector type remains the same regardless of
sex. For example: The user can replace an SMA female connector with an SMA male, however, an SMA connector
cannot be replaced with Type-N. Field replacement of the connector voids calibration and should only be done where
calibration is not required.
USB Considerations
The Universal Serial Bus (USB) provides adequate power for the sensor under normal circumstances. However, when
using a longer cable (greater than 3-5 meters), or when some laptop or portable computers are used, an active or self-
powered hub may be required. These are available at most computer stores and often sell for under $20.00. The
sensor is powered directly via the USB cable and typically draws 450 mA at a nominal 5 VDC. An active hub will
compensate for the DC voltage drop beyond approximately 3-5 meters. The reason an active hub is recommended
when using a portable computer is to conserve the battery life of the computer. PowerSensor+™ products are USB 2.0
compliant. The following information is provided for reference when selecting a hub:
Bus-powered hub: Draws a maximum of 100 mA at power up and 500 mA during normal operation.
Self-powered hub: Draws a maximum of 100 mA and must supply 500 mA to each port.
Low power, bus-powered functions: Draws a maximum of 100 mA (often applies to portable computers).
High power, bus-powered functions: Self-powered hubs: Draws a maximum of 100 mA and must supply 500 mA to
each port.
Suspended device: Draws a maximum of 0.5 mA

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Product Manual PMA (Power Meter Application)
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More information related to USB
1. Supplied voltage by a host or a powered hub port is between 4.75 V and 5.25 V.
2. Maximum voltage drop for bus-powered hubs is 0.35 V from its host or hub to the hub output port.
3. Normal operational voltage for functions is 4.75 V (minimum).
How to identify the type of USB port
The PowerSensor+™ requires your computer to have USB 2.0 port(s) for correct operation. You can identify what
type of USB port you have using the following process:
Click Start and select Control Panel. Select the Performance and Maintenance category then pick the System icon.
Click the Hardware tab and select Device Manager as shown below. Now expand the Universal Serial Bus
controllersheading as shown and look for the word “Enhanced” or USB2 to indicate that USB 2.0 is present on your
computer.

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Product Manual PMA (Power Meter Application)
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Applications
The PowerSensor+™ line of products is designed specifically for the following measurement applications:
oGeneral Average and Pulse Power Measurements
oPower Measurements Requiring High Accuracy:
CW & Pulsed Signals
Narrow and Wide Band Signals: CDMA, W-CDMA,
QAM, OFDM, GSM, TDMA, QPSK, FSK, AM, FM
Recorders, Power Monitoring, and ALC Loops
oResearch & Development and Manufacturing
oMaintenance, Repair, Installation and Service
oCommunications
oRadar, Wireless, Satellite, Radio Links
Accessories Supplied
The product is shipped with the following items:
1. A sensor with selected hardware and software options.
2. Standard or optional return to factory warranty.
3. 2-meter high speed USB cable.
4. Software CD or USB flash drive, includes the following:
Data sheet.
This product manual.
A user application (GUI) –provides a means of making measurements.
Drivers –several interfaces are available.
Programming Guide with sample code.
5. Quick Start Guide and Quick Start Card.
6. NIST traceable calibration certification.
7. Packing list and invoice.

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Product Manual PMA (Power Meter Application)
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Specifications
Refer to the data sheet by individual model number for a complete listing of product specifications to include pulse
profiling capability (LB480A/LB680A only). Data sheets are available on-line at the company website –see Contact
Information.
Product Comparison Table:
Model Number and Description
SWR
Dynamic Range*
Avg
Pk & Pulse
Pulse Profiling
LB478A CW PowerSensor+
.01 –8.0 GHz (functional to 10 GHz)
1.15:1
-35 to +20 dBm
Yes
No
LB479A CW Wide Dynamic
Range PowerSensor+
.01 –8.0 GHz (functional to 10 GHz)
1.09:1
-60 to +20 dBm
Yes
No
LB480A Pulse Profiling Wide
Dynamic Range PowerSensor+
.1 –8.0 GHz (functional to 10 GHz)
1.09:1
-60 to +20 dBm
Yes
Yes
LB559A Microwave PowerSensor+
.01 –12.5 GHz
1.20:1
-55 to +20 dBm
Avg
No
LB579A Microwave PowerSensor+
.01 –18 GHz
1.20:1
-55 to +20 dBm
Avg
No
LB589A Microwave PowerSensor+
.01 –26.5 GHz
1.20:1
-55 to +20 dBm
Avg
No
LB679A Microwave PowerSensor+
.05 –20 GHz
1.20:1
-40 to +20 dBm
Yes
No
LB680A Pulse Profiling
Microwave PowerSensor+
.05 –20.0 GHz
1.20:1
-40 to +20 dBm
Yes
Yes
* CAUTION: Max Input = +20 dBm; Damage Level = +23 dBm (all models)

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Product Manual PMA (Power Meter Application)
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Options
Refer to the order guide by individual model number for all product options. Order guides are available on-line at the
company website –see Contact Information.
Warranty
The warranty on the LadyBug PowerSensor+™ series of products is one year, return to factory. Extended warranty
and calibration service options are available. Please see the Order Guide for details.
SPECIAL NOTE: The RF input connector is field replaceable if the connector type remains the same, regardless of
sex. For example, the user can replace an SMA female connector with an SMA male; however, an SMA connector
cannot be replaced with Type-N. Field replacement of the connector voids calibration and should only be done where
calibration is not required.
Service
There are no serviceable parts on the LadyBug PowerSensor+™ series of products. Recommended service is return
to factory for repair. A high-quality connector saver (adapter) can be used on the RF input connector to extend the
useful life of the factory installed connector.
Calibration Cycle
The recommended calibration cycle for the LadyBug PowerSensor+™ series of products is one year, return to factory.
Extended warranty and calibration service options are available. Please see the Order Guide for details.
Contact Information
LadyBug Technologies LLC
3317 Chanate Rd. Suite 2F
Santa Rosa, CA 95404
Phone [phone]
Fax [phone]
www.ladybug-tech.com

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Product Manual PMA (Power Meter Application)
Revision: 08/02/11 - 9 -
2. Installation
Initial Inspection
Check the shipment for any damage to the shipping container or the components inside.
Support Contact Information
LadyBug Technologies LLC
3317 Chanate Rd. Suite 2F
Santa Rosa, CA 95404
Phone [phone]
Fax [phone]
www.ladybug-tech.com
Operating System and Computer Requirements
The PowerSensor+™ line of products is compatible with Windows 2000 (SP2 or greater), Windows XP, and Windows
7 operating systems with version 4.5 LB software. Support is available for various test development environments
including MS Visual Basic 6.0; MS Visual Basic .NET; MS C# .NET; NI LabVIEW; NI LabWindows; and Agilent VEE.
Recommended PC configuration:
Pentium D
1G RAM
1.0 GHz Processor
CD Drive
USB 2.0 Port*
* The USB port or hub must supply 500 mA @ 5 V for each power sensor operation. Refer to the USB Considerations
section of this manual to determine if your computer has a USB 2.0 port(s).
Installation Procedure
Install the Software
Refer to the Quick Start Card (Windows XP or Windows 7) to install the version 4.5 software.

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Product Manual PMA (Power Meter Application)
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3. Basic Operating Instructions –Getting Started
Operating Precautions
Observe the cautions and warnings about maximum input power in the specifications section. Insure that the RF input
connector on the sensor is clean and undamaged as well as the mating connector. The following procedures assume
the software and hardware have been installed according to the installation process outlined in the preceding section
of this manual.
Program Start Up
Starts the software if it is not currently running by clicking on the desktop icon labeled “Power Meter Application” or
launch it from its program location (select Start > All Programs > LB Technologies LLC > LB Power Meter Application).
Sensor(s) are selected by serial number if more than one sensor is connected to the computer. The serial number is
stamped below the USB port on the sensor body. We will be using the LB480A user interface for demonstration
purposes throughout this document. You may not have the LB480A sensor but the interface is common to all models
in the power meter configuration.
The GUI comes up by default in the average power or CW mode of operation for all models; frequency is set to 1 GHz;
averaging is set to 75 measurements; the measurement update rate is medium; offsets and frequency response are
disabled. These parameters are accessible from the Measurement menu. The Preset button will return the interface
to the default state. (There will be no Pulse Power mode of operation for the LB5XXA CW power sensor). Refer to the
GUI Functions section of this manual under Detailed Operating Instructions for more information about configuring the
sensor.
A separate GUI with unit model, serial number and address will appear for each active device when you open a new
instance of the Power Meter Application.The GUI allows identification of the individual sensor(s) by blinking the LED
on the sensor body. Clicking the ID button shown above will cause the LED on the sensor to blink four times in quick
succession. The ID and Preset functions are duplicated on the Measurement menu.

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Product Manual PMA (Power Meter Application)
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Configuring the Sensor
Measurement Update Rate
The measurement rate can be adjusted by selecting Meas Update Rate from the Measurement menu as shown
below. Other items on the Measurement menu are explained in the GUI Functions section of this document. The
application will take longer to respond to mouse clicks and data entry as the measurement rate is increased.
Addressing the Sensor
The Set Address facility allows the address of the sensor(s) to be assigned from 1 to 255. Changing the address
requires an automatic re-start of the application. You will see the following sequence of windows when changing the
address by selecting Set Address from the Measurement menu. Follow the instructions as stated to change the
address and to disconnect and reconnect the sensor.
Change address Screen #1
Change address Screen #2
Change address Screen #3

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Product Manual PMA (Power Meter Application)
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Making Basic Measurements
This manual applies to models LB478A, LB479A and LB480A as well as models LB559A, LB579A and LB589A. All
sensors function identically for CW measurements. The significant difference between these sensors is the ability to
make pulse measurements.
The sections of this manual that focus on pulse measurements apply only to models LB478A, LB479A and LB480A .
These sensors will be collectively referred to as LB4XXA sensors throughout the remainder of this manual. The
LB4XXA sensors can make both CW and pulse (modulation) measurements. The LB559A, LB579A and LB589A will
be collectively referred to as LB5XXA sensors. The LB5XXA sensors can make broadband CW measurements only.
These CW measurements are thermally compensated, true RMS measurements.
Zeroing and Reference Power Calibration
The design of the power sensor does not require zeroing or power calibration and there is no provision for zeroing or
calibration.
NOTE: While zeroing is not required for any LadyBug sensor, the LB5XXA sensors require time to thermally stabilize.
Little if any warm-up time is required for measurements above -40.0 dBm. However, to make accurate measurements
below -40 dBm the LB5XXA sensor should be allowed to thermally stabilize for one hour.
Setting the Center Frequency
Set the center frequency (GHz) as shown below. The center frequency must be set whenever the incoming signal
frequency changes. Measurement accuracy requires the frequency to be set and not doing so can be a significant
source of error. The frequency can also be set by sliding the analog frequency scale pointer just below the active
display. The pointer will change color from blue to red when the center frequency is beyond the measurement range of
the sensor. The pointer is less accurate but more convenient than entering a frequency value. You can also set the
frequency by selecting Measurement > Set Frequency from the menu bar (not shown) .

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Product Manual PMA (Power Meter Application)
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Display Preferences and Measurement Units
Select the display preferences and the measurement units (power and frequency) from the Display menu as shown
below. There are selections for digital or analog presentations of frequency and power; an analog frequency scale;
and an analog power scale. You can switch between displays and size the display as needed between compact and
very compact. Refer to the GUI functions section of this manual for an explanation of Limits.
Default Size & Layout
Compact Display

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Product Manual PMA (Power Meter Application)
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The power and frequency units are also selectable from the toolbar as shown below. Or you can change the power
units by clicking on the units label to the right of the power reading itself. And you can change the center frequency by
clicking anywhere on the frequency reading in the active display.
Measurement Resolution
The amplitude resolution is fixed to a thousandth of a measurement unit. Frequency is selectable in MHz or GHz
ranges.
Instrument Preset
The Preset button returns the unit to the following default state:
Mode = CW
Frequency = 1 GHz
Frequency units = GHz
Power units = dBm
Averaging = 75
Measured Pulse Setup = 3 dB (See Pulse Peak Criteria for LB4XXA only)
Measurement Update Rate = medium
Display = default
Sweep Time = 1 msec
Offset = 0 dB, disabled
Response = 0 dB, disabled
Duty Cycle = 10%, disabled
Minimum Loss Pad (75 ohm) = not selected*
Trigger Mode = Internal Continuous
Trigger Out = disabled
Recorder = disabled
*Preset will not change the input impedance if checked (enabled). Application launch sets the input to 50 ohms.

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Product Manual PMA (Power Meter Application)
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Making an Average Power (CW) Measurement
Complete the following steps to make a typical CW measurement (all models):
1. Using a signal generator or other appropriate source, provide a signal source with the following parameters:
CW Frequency: 1 GHz
Power Level: 0 dBm (1 mW)
Modulation: OFF
RF Power: OFF
WARNING: DO NOT EXCEED +23dBm, 200mW, or 3.15VRMS. Refer to the specifications in the
product data sheet for maximum allowable limits by model number.
2. Setup the GUI to receive the RF source input as shown below including the power and frequency units. All
parameters shown can be disabled for this example except for Triggering (option 003), which can be set to
continuous and internal:
Select: Measurement > CW Power (or activate the CW button on the toolbar for LB4XXA models only). The
application is always in the CW mode for LB5XXA models so the button is not present.
Select: Measurement > Set Frequency
Enter: 1 GHz
Select: (Optional) Triggering > Continuous > Internal
3. Connect the sensor to the RF source and turn the RF power on.
4. The GUI display should now indicate approximately ~0 dBm at 1 GHz.
5. Vary the source power to see if the GUI display tracks the source power.

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Making a Pulse Power Measurement
Complete the following steps to make a typical pulse power measurement (LB4XXA models only):
1. Using a signal generator or other appropriate source, set the RF source for a pulse modulated output as indicated
below:
Power Level: 0 dBm (1 mW)
CW Frequency: 1 GHz
PRF 10 kHz (or a PRI of 0.1 msec)
Pulse Modulation: 50% Duty Cycle (or a pulse width of 50 usec)
RF Power: OFF
WARNING: DO NOT EXCEED +23dBm, 200mW, or 3.15VRMS. Refer to the specifications in the
product data sheet for maximum allowable limits by model number.
2. Setup the GUI to receive the RF source input as shown below including the power and frequency units. All
parameters shown can be disabled for this example except for Triggering (option 003), which should be set to
continuous and internal:
Select: Measurement > Pulse Power (or activate the Pulse button on the toolbar for LB4XXA models only)
Select: Measurement > Set Frequency
Enter: 1 GHz
Select: (Optional) Triggering > Internal > Continuous
The active display above indicates input Duty Cycle (DC); Peak power (Pk); Average power (Avg); and Crest
Factor (CrF) when in the Pulse Power mode. The larger reading indicates the pulse power. The default setup is the
automatic or 3 db points below peak power. This “dB below peak” value can be changed by de-selecting automatic
and entering a different value if the specific pulse characteristics are known. Refer to the “Pulse Measurement
Criteria” and “Pulse Peak Criteria” sections of this manual under Detailed Operating Instructions for further
information.
NOTE: Crest Factor is otherwise known as PAR (Peak to Average power Ratio).

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3. Connect the sensor to the RF source and turn the RF power on.
4. The GUI display should now indicate the source power at 1 GHz: ~0 dBm pulse power; ~50% DC; ~0 dBm peak;
~-3 dBm average; and ~3 dB CrF (Crest Factor is the ratio between peak and average power or PAR).
5. Vary the source power and duty cycle to see if the GUI display tracks the source.
PowerSensor+™ measurements are real time presentations of power. They are not a type of calculated measurement
made by most CW sensors. You will note a corresponding change in the duty cycle reported in the GUI if you change
the duty cycle of your source. You will note a change in the pulse envelope power (the large display), peak power, and
average power if you change the power level. The duty cycle will remain unchanged.
The LB479A can measure 350 nsec pulses at -55 dBm (and lower) with a PRF of 1 kHz (or lower). Such
measurements require averaging to be set between 5000 and 10000.
Alternate Pulse Measurement using Duty Cycle
PowerSensor+™ sensors can make the more traditional pulse measurement using an assumed duty cycle as an
adjustment to the indicated power. This type of measurement is less accurate and more prone to error because of the
pulse shape factor; and because the duty cycle is assumed. However, this a useful measurement approach
using the LB5XXA line of instruments.
The duty cycle correction is calculated as follows:
Pulse Power = Measured Power + Duty Cycle Adjustment
The duty cycle adjustment is: - (10Log10 (Duty Cycle))
For instance, if you measured an average power of -20 dBm and assumed a duty cycle of 10% (0.10) then the pulse
power would be calculated as follows:
Pulse Power = -20 dBm + -(10Log10 (Duty Cycle)) = -20 dBm + (10 dB) = -10dBm
The sensor must be placed in CW Power mode to access this style of duty cycle measurement.

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Product Manual PMA (Power Meter Application)
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Follow the steps below demonstrating this more traditional pulse measurement using duty cycle:
1. Setup the interface by selecting the following parameters as shown below.
Select: Measurement > CW Power (or activate the CW button on the toolbar - not required for LB5XXA)
Select: Offsets & Response > Duty Cycle > Setup
Enter: 10 (%)
Select: Offsets & Response > Duty Cycle > Enabled (or activate the DC icon on the toolbar)
2. The display will report source pulse power in the CW configuration and the DC annunciator will activate. The duty
cycle can be used down to about 0.1%.

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4. Detailed Operating Instructions
Measurement Overview and Examples
The Power Meter Application
The LB4XXA and LB6XXA series of RF sensors makes Avg and pulse (modulation) measurements in a 10 MHz video
bandwidth. The LB5XXA series of microwave sensors makes CW or true average power measurements up to 26.5
GHz. (The LB480A and LB680A sensors are also capable of making pulse profile measurements –refer to the Quick
Start Guide and Product Manual for the Pulse Profiling Application).
The pulse power mode of operation displays pulse power (average power in the pulse); pulse duty cycle; peak pulse
power; average power; and Crest Factor (CrF) or the peak to average power ratio. This mode applies to the LB4XXA
sensors only. The LB4XXA/LB6XXA sensors are capable of more than 2000 settled readings per second.
There is provision for logging measurements to file and pass/fail limit checking on all models. Various trigger methods
are available to allow the measurement of continuously modulated signals or single events.
Refer to the block diagram in the Measurement Accuracy section of this document for the following discussion: The
incoming broadband RF/microwave energy is first conditioned and converted to digital format. The input power drives
two measurement channels of differing sensitivity. The transition between these paths is typically between -30 and -
20 dBm. Most LadyBug power sensors continually digitize both paths simultaneously and use a weighted average
approach over the transition range. This approach to the measurement means that a seamless measurement
transition between paths is possible. It also means that the full dynamic range of the sensor is available to all
measurements all of the time.
By contrast, sensors produced by other manufacturers measure only one path at a time. This requires that the
transition be managed after an errant measurement has been made. This makes the transition between any two
ranges a point of potential discontinuity or hysteresis. As a result, minor differences in the calibration between the two
paths can often result in constant and annoying switching between paths. Constant path switching can produce a
noticeable jump in power level readings. Another and perhaps more detrimental effect is that this approach guarantees
that the full dynamic range of the sensor is not available to any given measurement. Ladybug has resolved these
range transition problems.
The LB4XXA and LB6XXA sensors are capable of making pulse (modulation) measurements. These pulse
measurements are possible because the LB4XXA sensors employ a 10 MHz video or modulation bandwidth.
Discussions about bandwidth are generally accompanied by concerns about making an aliased measurement. Though
uncommon in practice, aliasing can and does occur. LadyBug sensors can randomize the sampling in order to
minimize or eliminate the possibility of making an aliased measurement. However, this sampling randomization is
accompanied by a small performance penalty. Rather than penalize all measurements we allow the user to favor
performance (speed of measurement), or guard against aliasing. This choice is presented on the user interface as an
anti-aliasing option.
The display toolbar has an anti-aliasing control button that is used for CW and continuous pulse measurements only. It
is generally useful for the LB4XXA/LB6XXA sensors where the video content is greater than 200 kHz. This feature
guards against making aliased measurements for modulation bandwidths greater than 200 kHz. It actually determines
the sampling method that is employed for the particular modulation bandwidth - either narrow or wide. The toolbar
functions are explained in greater detail in the GUI Functions section of this manual.
The Pulse Profiling Application
The LB480A/LB680A are specifically designed for those applications requiring a time domain analysis of pulse and
other modulated signal formats. Refer to the Quick Start Guide and Product Manual for the Pulse Profiling Application.

LBXXXA Series USB PowerSensor+™
Product Manual PMA (Power Meter Application)
Revision: 08/02/11 - 20 -
Pulse Measurement Criteria (LB4XXA/LB6XXA models only)
This value determines the portion of the pulse to be used to measure pulse power. Select Measurement > Measured
Pulse Setup from the menu bar to access this facility as shown below. The default or automatic value is 3 dB below
the measured peak value or the 50% down points. You can also set the criteria and leave the automatic feature on.
Then by turning the auto feature on and off you can switch between the automatic value (dB) and the value you have
chosen. For instance, if you set the criteria to 6 dB and turn the auto criteria on and off, you will be toggling between 3
dB and 6 dB below peak. This can also give you some sense of rise time or slope and the sensitivity to this criteria.
Pulse criteria is assumed to be specifed as “dB below peak.” If the peak value is -30 dBm and the criteria is 3 dB, then
the pulse criteria will be -33 dB during the measurement. Normally you will specify a positive value. Likewise, if you
chose 6 dB you would be using -36 dB as the criteria. Provided overshoot is minimal and rise time is relatively steep,
the automatic criteria is adequate for most applications. The diagrams below are intended to help clarify pulse criteria.
In diagram A, the peak value is -30 dBm and the pulse criteria is 3 dB. The shaded area represents the portion of the
pulse that will be used to determine pulse power and duty cycle.