1. Manuals
  2. Brands
  3. SteppIR Manuals
  4. Measuring Instruments
  5. SARK-110
  6. User manual

SteppIR SARK-110 User Manual

Vector impedance antenna analyzer
Hide thumbs
Table of Contents

Advertisement

Quick Links

Download this manual
SARK-110
Vector Impedance Antenna Analyzer
User's Manual
Revision 1.1.7
This document is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
© Melchor Varela – EA4FRB 2011-2014

Advertisement

Table of Contents
loading
Need help?

Need help?

Do you have a question about the SARK-110 and is the answer not in the manual?

Questions and answers

Summary of Contents for SteppIR SARK-110

  • Page 1 SARK-110 Vector Impedance Antenna Analyzer User’s Manual Revision 1.1.7 This document is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. © Melchor Varela – EA4FRB 2011-2014...
  • Page 2 SteppIR SARK-110 User’s Manual Updated to Firmware Version 0.8.x Rev 1.1.7 October 29 , 2014 - 2 - © Melchor Varela – EA4FRB 2011-2014...

  • Page 3: Table Of Contents

    SteppIR SARK-110 User’s Manual Contents INTRODUCTION ........................5 MAIN FEATURES ........................6 OVERVIEW OF FUNCTIONS ....................7 OPERATING THE STEPPIR SARK-110 .................. 8 ........................8 CREEN AYOUT ....................10 TATUS YMBOLS EANING ........................ 10 EANS OF NPUT ....................11 HANGING THE REQUENCY ......................
  • Page 4 SteppIR SARK-110 User’s Manual COMPUTER CONTROL MODE ..................51 TRANSMISSION LINE ADD/SUBTRACT ................53 SPECIFICATIONS ....................... 56 PRECAUTIONS ........................60 REGULATORY WARNING ....................60 ACKNOWLEDGMENTS ..................... 61 APPENDIX A: THEORY OF OPERATION ................62 APPENDIX B: FUNDAMENTAL PARAMETERS ..............65 APPENDIX C: UPGRADING THE FIRMWARE ..............

  • Page 5: Introduction

    The Multiband mode is a unique feature of the SteppIR SARK-110 whereby it is able to display simultaneously the plot of an impedance parameter in four scalar charts. This feature is ideal for tuning multiband antennas.

  • Page 6: Main Features

    SteppIR SARK-110 User’s Manual measured parameters can be downloaded to a PC for analysis using the ZPLOTS spreadsheet program or with SteppIR SARK Plots client software for Windows. Please let us have your suggestions through the website http://www.sark110.com as we are highly motivated to extend this device’s functionality based on community requests.

  • Page 7: Overview Of Functions

    SteppIR SARK-110 User’s Manual 3 Overview of Functions Navigator A Select Save Conf. Navigator B Run/Hold Save Screen é ê -•••+ ••• Ø|| Test Port Test Port Mini USB Port Power Switch SARK-110 3" TFT LCD The unit has a Test Port located on the left side to connect to the device under test. This receptacle accepts straight MCX plug connector types.

  • Page 8: Operating The Steppir Sark-110

    4.1 Screen Layout The following figure shows the screen layout in Scalar Chart mode. It shows diagram areas that are the same for all operating modes of the SteppIR SARK-110. Screen layouts that show specifics for each operating mode...
  • Page 9 SteppIR SARK-110 User’s Manual Highlighted submenu option Run/Hold status Currently selected submenu option USB/Battery status Rev 1.1.7 October 29 , 2014 - 9 - © Melchor Varela – EA4FRB 2011-2014...

  • Page 10: Status Symbols Meaning

    Charge status of the battery when the device is operating from the battery Disk Disk write operation in progress 4.3 Means of Input There are four buttons and two navigation keys on the SteppIR SARK-110. Save Conf. Navigator A Select Save Screen...

  • Page 11: Changing The Frequency

    SteppIR SARK-110 User’s Manual The Run/Hold button is used to control the operating state of the SteppIR SARK-110: Working or Paused. In the paused state the signal generator and measurement circuits are inactive. Ø Note: when loading a stored data file the analyzer is automatically placed in a paused state.

  • Page 12: Changing The Span

    SteppIR SARK-110 User’s Manual (ii) Use Navigator A to highlight «Freq» in the main menu on the left side of the display. Then use Navigator B to change the frequency. The frequency will change according to the current frequency multiplier. The frequency multiplier can be changed from the popup dialog, see (i) above.

  • Page 13: Frequency Presets

    See in the screenshot below the available presets: 4.7 Using Markers The SteppIR SARK-110 has two markers that can either be manually positioned by the user or set to operate in automatic tracking mode. The markers indicate the horizontal and vertical position of Rev 1.1.7 October 29...
  • Page 14 SteppIR SARK-110 User’s Manual the point they are positioned on. The horizontal position of a marker is shown by a dotted vertical line which extends from the top to the bottom of the measurement diagram. The markers information window, in blue background, shows the frequency or distance (in cable test mode) and the two values that correspond to the plotted values at each of the markers.
  • Page 15 SteppIR SARK-110 User’s Manual  Peak Min (p)  Peak Max (P)  Absolute Min (m)  Absolute Max (M)  Value Cross Any (X)  Value Cross Up (^)  Value Cross Down (v) The automatic positioning of markers is activated in the «Tracking» sub-option. Select the tracking mode from any of the modes above and then the applicable parameter to track.

  • Page 16: Changing The Vertical Axis Parameter

    User’s Manual 4.8 Changing the Vertical Axis Parameter In Scalar Chart mode, the SteppIR SARK-110 can display two traces from any of the available parameters for the vertical axis. Use Navigator A to highlight either «LeftY» or «RightY» in the main menu.

  • Page 17: Saving And Recalling Measurements

    User’s Manual 4.9 Saving and Recalling Measurements The SteppIR SARK-110 has the capability to store measurements to the internal disk and recall them either to review the data later in the analyzer screen or to download the data from the USB disk to a PC for further analysis using SARK Plots or the ZPLOTS Excel application, available from http://www.ac6la.com/zplots.html.
  • Page 18 SteppIR SARK-110 User’s Manual «Load Data File» To retrieve the stored data, select the «Load Data File» submenu option. A second popup submenu is displayed with a list of available files. Use Navigator B to highlight the desired file. Press the Select [■] button to validate the selection.
  • Page 19 SteppIR SARK-110 User’s Manual «Browse Bitmaps» Select the option «Browse Bitmaps» from the «File» menu to review the captured screenshots. Use Navigator B to select the different bitmaps. Press the Select [■] button to finalize the operation. «Delete File» Use the «Delete file» option to delete a single file on the device disk.

  • Page 20: Taking Screenshots

    SteppIR SARK-110 User’s Manual 4.10 Taking Screenshots Press the Save Screen [●] button to capture the current screen. Then enter the file name. By default the file name has the format “sark_xxx.bmp”, where xxx is an automatically assigned number. To change the file name, use Navigator B to change the character value and Navigator A to change the character position highlighted in inverse video.

  • Page 21: Changing The Settings

    SteppIR SARK-110 User’s Manual Use Navigator B to highlight the desired submenu mode option. Press the Select [■] button to validate the selection. Press any other button to cancel the operation. 4.12 Changing the Settings Use Navigator A to highlight «Setup» in the main menu.
  • Page 22 See Appendix F: Setup - Scale The SteppIR SARK-110 provides three pre-defined scale values: Normal, High, and Low as well as automatic scaling. This setting defines the maximum and minimum values for each parameter on the Y axis, see Appendix H:. This setup is valid for the Scalar Chart, Field, and Multi-band modes.
  • Page 23 SteppIR SARK-110 User’s Manual Setup - Z0 This setting allows the reference characteristic impedance to be changed. The value can be selected from a set of predetermined values or it can be user-specified selecting the Custom option. Setup - Automatic Power Off This setting allows the automatic power off delay to be selected from a set of predefined times.
  • Page 24 SteppIR SARK-110 User’s Manual After power-off, press the Select [■] button to resume the operation. Alternatively, power off and power on the device using the Power Switch. Setup - Cable Type The length measurements in the cable test mode and transmission line operations require the proper setting of the cable type.
  • Page 25 SteppIR SARK-110 User’s Manual Rev 1.1.7 October 29 , 2014 - 25 - © Melchor Varela – EA4FRB 2011-2014...
  • Page 26 SteppIR SARK-110 User’s Manual In the screenshot below the circle has been changed to a VSWR of 5.0 Setup – Color Theme This setup permits the choice from two color theme options: «Black» or «White». The screenshots below shows graphs with color theme set to «White» and «Black»: Rev 1.1.7 October 29...
  • Page 27 SteppIR SARK-110 User’s Manual Setup – Plot Thickness This setup allows choice of thickness of the diagram’s traces from two options: «Thick» and «Thin». This option is unavailable in the Field Mode graph, where traces are always set to thick.
  • Page 28 SteppIR SARK-110 User’s Manual The screenshots below shows graphs with plot thickness set to «Thick» and «Thin»: Setup – Filter This setup offers the choice of one of two noise reduction filters or none for the Scalar Chart, Smith Chart, Field, and Multi-band modes.
  • Page 29 SteppIR SARK-110 User’s Manual The «Average» filter minimizes the noise but at the expense of reducing the measurement speed. Four samples are taken for each measurement frequency and an average from these samples is calculated. The «Smoothing» filter is a moving average calculation for each measurement point the unweighted mean of the previous measurement points.
  • Page 30 SteppIR SARK-110 User’s Manual Setup – Sampling This setup allows choice of the number of measurement samples from two options: «Normal / fast» or «Double / slow». The «Normal / fast» option is the default setting and the more convenient for most cases.
  • Page 31 SteppIR SARK-110 User’s Manual Setup – About The about screen displays copyright information, firmware release number, disk size and free space. Rev 1.1.7 October 29 , 2014 - 31 - © Melchor Varela – EA4FRB 2011-2014...

  • Page 32: Scalar Chart Mode

    SteppIR SARK-110 User’s Manual 5 Scalar Chart Mode Diagram Frequency and span settings Traces Transmission Line length setting Markers Reference impedance setting Vertical axis labeling Loaded data file name Frequency axis labeling Disk write operation in progress Main menu Calibration status...
  • Page 33 SteppIR SARK-110 User’s Manual to provide precise information in the plotted areas. Their positions can either be user-selected or automatically tracked. They are also useful for indicating characteristic points in the plot. Use Navigator A to highlight «Mode» in the main menu. Press the Select [■] button to activate the Mode popup submenu and use Navigator B to highlight «Scalar Chart»...

  • Page 34: Smith Chart Mode

    SteppIR SARK-110 User’s Manual 6 Smith Chart Mode Diagram Frequency and span settings Trace Transmission Line length setting Markers Reference impedance setting Constant impedance circle Loaded data file name Frequency start and end Disk write operation in progress Main menu...
  • Page 35 SteppIR SARK-110 User’s Manual Use Navigator A to highlight «Mode» in the main menu. Press the Select [■] button to activate the Mode popup submenu and use Navigator B to highlight «Smith Chart» submenu mode option. Finally press the Select [■] button to enter into Smith Chart mode.

  • Page 36: Single Frequency Mode

    SteppIR SARK-110 User’s Manual 7 Single Frequency Mode VSWR bar Detailed measurements Series impedance complex form Detailed measurements extended Circuit equivalent series Frequency setting Series resistance and equivalent Transmission Line length setting inductance (or capacitance) values Parallel impedance complex form...
  • Page 37 SteppIR SARK-110 User’s Manual VSWR graph is available for a quick visualization of this parameter. As well as the two element equivalent circuit models, both series and parallel circuits are displayed as schematics. Use Navigator A to highlight «Mode» in the main menu. Press the Select [■] button to activate the Mode popup submenu and use Navigator B to highlight «Single Frequency»...

  • Page 38: Cable Test Mode (Tdr)

    Cable Test or Time Domain Reflectometer (TDR) mode is intended to identify potential coaxial cable faults that could disrupt signal transmission. Unlike native TDR test equipment, the method of measurement in the SteppIR SARK-110 is based on the theory of Frequency Domain Reflectometry (FDR).
  • Page 39 SteppIR SARK-110 User’s Manual The analyzer makes swept reflection measurements over the entire frequency range and mathematically transforms the gathered data to Time Domain using an inverse Fourier transform. As a result, the step and impulse responses are plotted on the display, providing information about the location and the nature of any fault.
  • Page 40 SteppIR SARK-110 User’s Manual Figures below illustrate the responses of known discontinuities: Rev 1.1.7 October 29 , 2014 - 40 - © Melchor Varela – EA4FRB 2011-2014...
  • Page 41 SteppIR SARK-110 User’s Manual Element Impulse Response Step Response Display Open Unity reflection Unity reflection Short Unity reflection, -180º Unity reflection, -180º Resistance R > Z Positive peak Positive level shift Resistance R < Z Negative peak Negative level shift...

  • Page 42: Field Mode

    SteppIR SARK-110 User’s Manual 9 Field Mode Diagram Transmission Line length setting Trace Reference impedance setting Vertical axis labeling Loaded data file name Frequency axis labeling Disk write operation in progress Maximum and minimum values Calibration status Highlighted menu option...
  • Page 43 SteppIR SARK-110 User’s Manual Use Navigator A to highlight «Mode» in the main menu. Press the Select [■] button to activate the Mode popup submenu and use Navigator B to highlight «Field» submenu mode option. Finally press the Select [■] button to enter into Field mode.

  • Page 44: Multi-Band Mode

    The Multiband mode is a unique feature of the SteppIR SARK-110 to display the plot of an impedance parameter in four scalar charts simultaneously. This feature is ideal for tuning multiband antennas. Additionally, it can be used to display different views of the same band, as a kind of zoom feature.
  • Page 45 SteppIR SARK-110 User’s Manual Use Navigator A to highlight «Mode» in the main menu. Press the Select [■] button to activate the Mode popup submenu and use Navigator B to highlight «Multi-band» submenu mode option. Finally press the Select [■] button to enter into Multi-band mode.

  • Page 46: Signal Generator Mode

    User’s Manual 11 Signal Generator Mode The SteppIR SARK-110 can be used as a programmable RF signal source in Signal Generator Mode. It outputs a sinusoidal RF signal at a frequency programmable from 100 kHz to 230 MHz with eight user selectable amplitude levels ranging from -73 dBm to -10 dBm. In addition, frequency sweeps can be programmed with linear, bi-linear, logarithmic, or bi-logarithmic functions.
  • Page 47 SteppIR SARK-110 User’s Manual The signal generator outputs continuously unless it is paused by pressing the Run/Hold [►||] button. In the Hold state the level graph and power level indicators change to red. Signal generation can be resumed at any time by pressing the same button again.
  • Page 48 SteppIR SARK-110 User’s Manual In frequency sweep mode the signal frequency will sweep across a range of provided frequencies. To change the sweep parameters, use Navigator A to highlight «Sweep» in the main menu and press the Select [■] button to validate the different sweep parameters.
  • Page 49 SteppIR SARK-110 User’s Manual Rev 1.1.7 October 29 , 2014 - 49 - © Melchor Varela – EA4FRB 2011-2014...
  • Page 50 Another useful output power level value for receiver testing is -107dBm, which is 1uV into 50 ohms and equates to S1 on an S-meter. This power level is not available in the SteppIR SARK-110, but a 34dB attenuator could be made to give -107dBm with a pi network of two 52 ohm resistors as shunt in and out and a 1.2k + 52 ohm series resistor.

  • Page 51: Computer Control Mode

    User’s Manual 12 Computer Control Mode The SteppIR SARK-110 can be operated from a personal computer using SARK Plots client software for Windows, further enhancing the capabilities of the instrument. There is no need to install a dedicated driver since the communication is implemented using the standard USB HID interface.
  • Page 52 SteppIR SARK-110 User’s Manual The command interface specification is open for anyone wishing to develop client software. Source code examples of the communication interface are available for different operating systems. This information is available at the following link: http://www.sark110.com/commands-interface Rev 1.1.7 October 29...

  • Page 53: Transmission Line Add/Subtract

    Use the addition feature for simulating the effect of a feed line. The transmission line type has to be known in advance. The SteppIR SARK-110 provides a comprehensive list of cable types and in addition the user can specify up to three custom cable types.
  • Page 54 As a precondition the cable must be unterminated at the far end. Set the SteppIR SARK-110 to Smith Chart mode and select «Preset» «Full HF». The Smith Chart will show a spiral from infinite impedance and going towards the centre. When setting negative length values, this spiral will be progressively unrolled and transposed to the infinite impedance point when the exact length will be set.
  • Page 55 SteppIR SARK-110 User’s Manual Rev 1.1.7 October 29 , 2014 - 55 - © Melchor Varela – EA4FRB 2011-2014...

  • Page 56: Specifications

    SteppIR SARK-110 User’s Manual 14 Specifications Synthesizer  Direct Digital Synthesis with 1Hz resolution  Sine wave output  Frequency range from 0.1 to 230Mhz Measured Complex impedance (series and parallel) and reflection coefficient in rectangular and polar form, VSWR, return loss, reflection power...
  • Page 57 SteppIR SARK-110 User’s Manual Cable Test Mode  Maximum length: about 250 m  Displays step and impulse responses Field Mode  Graphical plot of one user-selected parameter in a scalar chart with enhanced legibility  Display max and min values Multi-band Mode ...
  • Page 58  Operating temperature: 0ºC to 50ºC Dimensions 98 * 60 * 14.5 (mm) Weight 120g Package Content  SteppIR SARK-110 x 1  Battery x 1 Rev 1.1.7 October 29 , 2014 - 58 - © Melchor Varela – EA4FRB 2011-2014...
  • Page 59 SteppIR SARK-110 User’s Manual  MCX to BNC adapter pigtail x 1  Allen key x 1 Rev 1.1.7 October 29 , 2014 - 59 - © Melchor Varela – EA4FRB 2011-2014...

  • Page 60: Precautions

    SteppIR SARK-110 User’s Manual 15 Precautions 1. Never connect the unit to an antenna during a lightning storm. Lightning strikes and static discharges can damage the unit and may kill the operator. 2. Never apply an RF signal or any other external voltage to the test port of this unit. Doing so may damage the unit.

  • Page 61: Acknowledgments

    SteppIR SARK-110 User’s Manual 17 Acknowledgments  I would like to offer a special thanks to the Seeed Studio team for making this product a reality.  The analyzer schematics and layout have been developed using the DesignSpark PCB tool.

  • Page 62: Appendix A: Theory Of Operation

    The block diagram below illustrates the main functional blocks of the SteppIR SARK-110 Antenna Analyzer: The SteppIR SARK-110 comprises four main sections: a signal generator used as an active source, a bridge to provide signal separation, two tuned receivers that downconvert and detect the signals and a microcontroller and display for calculating and reviewing the results.
  • Page 63 DDS designs use a broadband balun transformer to convert to single end mode but because of the restricted height available in the SteppIR SARK110 enclosure a silicon-based solution was chosen. The output of each amplifier is followed by elliptic low pass filters with a cut-off frequency of 230 MHz.
  • Page 64 SteppIR SARK-110 User’s Manual Rev 1.1.7 October 29 , 2014 - 64 - © Melchor Varela – EA4FRB 2011-2014...

  • Page 65: Appendix B: Fundamental Parameters

    SteppIR SARK-110 User’s Manual Appendix B: Fundamental Parameters Abbreviation Parameter Description Series resistance Resistive value of a series impedance Series reactance Reactance value of a series impedance Parallel resistance Resistive value of a parallel impedance Parallel reactance Reactance value of a parallel impedance...
  • Page 66 SteppIR SARK-110 User’s Manual Abbreviation Parameter Description <Rho Reflection It is a measure of the phase angle of the ratio of the Coefficient Angle amplitude of the reflected wave to the amplitude of the incident wave.   RhoI ...

  • Page 67: Appendix C: Upgrading The Firmware

    User’s Manual Appendix C: Upgrading the firmware The SteppIR SARK-110’s firmware may be upgraded via USB as described in the following steps: This procedure assumes you have downloaded the appropriate update file from: http://www.sark110.com/files/firmware Ø Note: Two versions of the zipped upgrade file are always available. This is explained on...

  • Page 68: Appendix D: Osl Calibration

    Appendix D: OSL Calibration The SteppIR SARK-110 provides a calibration procedure to compensate for the stray capacitance and impedance of the external test fixture, e.g. the extension cable. This should be performed every time the external test fixture is changed as well as periodically.
  • Page 69 SteppIR SARK-110 User’s Manual The calibration procedure is as follows: Connect the open load. Press the appropriate button to continue, or to exit. The calibration progress will be shown in the display bar. Connect the short-circuit load. Press the appropriate button to continue, or to exit.
  • Page 70 SteppIR SARK-110 User’s Manual Connect the reference load. Press the appropriate button to continue, or to exit. The calibration progress will be shown in the display bar. Press the appropriate button to apply the new calibration settings, or to cancel them.

  • Page 71: Appendix E: Frequency Calibration

    SteppIR SARK-110 User’s Manual Appendix E: Frequency Calibration This setup permits the frequency synthesizer to be calibrated to 1 Hz. The calibration operation is available at «Setup» «Calibration» «Frequency Calibration». To calibrate the synthesizer, select «Frequency Calibration» from the «Calibration» submenu and adjust the frequency while measuring it with an accurate frequency counter or, alternatively, zero- beat it against WWV.

  • Page 72: Appendix F: Detector Calibration

    Appendix F: Detector Calibration This procedure performs alignment of the SteppIR SARK-110’s internal measurement circuits. This operation is done once at the factory and it is not necessary for the user to repeat it, but the procedure is detailed for completeness.
  • Page 73 SteppIR SARK-110 User’s Manual The calibration progress will be shown in the display bar. Connect the 50-ohm load. Press the appropriate button to continue, or to exit. Connect the 100-ohm load. Press the appropriate button to continue, or to exit.
  • Page 74 SteppIR SARK-110 User’s Manual The calibration is completed. The calibration coefficients are shown at the bottom of the screen, for information. Press the appropiate button to apply the new calibration settings, or to cancel them. Rev 1.1.7 October 29 , 2014 - 74 - ©...

  • Page 75: Appendix G: Frequency Presets File

    SteppIR SARK-110 User’s Manual Appendix G: Frequency Presets File Default frequency presets can be modified by the user by supplying a special text file stored on the analyzer’s disk. The file name must be “presets.txt” and the format for each band entry in the file is...

  • Page 76: Appendix H: Scale Presets

    SteppIR SARK-110 User’s Manual Appendix H: Scale Presets Following tables show the default scale presets: Normal Scale High Scale 1000 5000 -500 Linear -2500 2500 Linear 1000 5000 -500 Linear -2500 2500 Linear |Zs| 1000 |Zs| 5000 <Zs -100 Linear <Zs...
  • Page 77 SteppIR SARK-110 User’s Manual Default scale presets can be modified by the user by supplying special text files stored on the analyzer’s disk. The file names for each of the scales have to be the following:  «Scale» «Normal»  “scal_def.txt”...

  • Page 78: Appendix I: Custom Cable Settings

    Appendix I: Custom Cable Settings The SteppIR SARK-110 allows the user to specify three custom cable settings by supplying a special text file stored on the analyzer’s disk. The file name must be “custcab.txt” and the format for each cable entry in the file is as follows:...

Table of Contents