The demo guide contains

Transcription

1 The demo guide contains 1. Demo configuration, units are available in the Agilent demstock 2. Remote Demo, a remote setup is available in Böblingen. Booking is possible via a demo outlook calendar. Please contact your regional MDM 3. Demo itself, how to start and do a demo using matlab scirpts 4. Troubleshooting

2 1.) Demo Configuration Hardware: - M9505A - 5 slot AXIe chassis with - M9536A - embedded PC (or standalone control PC) - M8190A #B02-2 channel AWG with 14 bit, 8 Gsample and 2 GSa memory per channel - Spectrum Analyzer (PSA, MXA or PXA) and/or - Oscilloscope (80k, 90k, 90kX models) - optionally: E8267A-#016 if you want to show I/Q up-conversion - optionally: Marki M2-0020LK (or similar) mixer to demonstrate regular up-conversion - Balun (is part of the M8190A demo kit) - bring your own: SMA cables, SMA to BNC adapters (scope), SMA-to-N adapter (for spectrum analyzer) Software (should all be pre-installed on M9536A embedded PC): - M8190A firmware, on the M8190 home page under software/driver - Soft-Frontpanel for AWG, download see link above - MATLAB with example scripts. Script download see link above. Matlab trial download: &id= VSA software for scope calibration A VSA Software can be downloaded from the Agilent web &id= Login Information (when using embedded PC M9536A with Agilent demo unit) Login: demouser Password: demo!123

3 Hardware Setup standard demo configuration: Labtop or Desktop PC or Embedded Controler (5-slot Demo system) 2-slot chassis w/ 1 AWG module or 5-slot chassis w/ 2 AWG modules max PCIe LAN Remote LAN connection LAN-switch (optional) The standard demo configuration that allows you to nicely demonstrate the signal performance of the M8190A in a variety of applications (except I/Q) is this. Ch1+ Ch1- M8190A Balun Spectrum A. Ch2+ Ch2-50 Ω 3 GHz filter Oscilloscope The balun in the path to the spectrum analyzer helps to suppress the 2 nd harmonics and allows you to generate a very clean multi-tone NPR signal with as much dynamic range as possible. The balun also acts as a low-pass filter (~5 GHz). The cables from the M8190A to the balun should be a matched pair. The 3 GHz filter in the path to the oscilloscope is optional, but it makes the signal look better in the timedomain. For demonstrating I/Q baseband signals, a slightly different setup is needed. This configuration is also suggested if no spectrum analyzer is available. M8190A Ch1+ Ch1- Spectrum A. Ch2+ Ch2-50 Ω Ch1 Ch3 Oscilloscope

4 In this configuration it is important to have a matched cable pair for the scope connection. The spectrum analyzer connection is optional. If it is not connected, the Ch1- output should be terminated with 50 Ohms. For I/Q up-conversion, yet another setup is required: Ch1+ Ch1- M8190A E8267D Spectrum A. Splitter Opt.016 Oscilloscope Ch2+ Ch2- Two matched cable pairs are required for this setup. Setup The MATLAB scripts that are used for the demo need to remotely control the spectrum analyzer and oscilloscope. One possibility to enable remote control is to connect LAN cables between the spectrum analyzer resp. scope to the RJ45 connectors on the front panel of the M9536A embedded PC or the LAN connector on the ESM interface board. Obviously, the IP addresses on the scope and spectrum analyzer need to be set up to be in the desired subnet. To verify the connection, try to ping the scope and spectrum analyzer from the embedded PC. Also, you will have to add the scope to the Agilent I/O Expert configuration so that it will be recognized by the VSA software. In addition to connecting additional instruments to these LAN ports, one of them can also be used to connect a laptop computer and run a Remote Desktop session from the laptop. This eliminates the need to bring a monitor, keyboard and mouse for the embedded PC. As an alternative to Remote Desktop, you can run the MATLAB scripts on your laptop computer.

5 2.) Remote Demo: How to make a remote connection to the BBN demosetup: Step 1: Connect to the control PC via Remote Desktop Connection. Therefore double click the AWG Demo.rdp file below. For further use of this connection Copy & Paste the AWG Demo.RDP to your desktop. Step 2: A login window appears. Enter the following credentials: Account: Password: CZC110BXPK\Instrument M8190A4u Password: M8190A4u Step 3: Start your demo.

6 3.) M8190A demo: How to start the demo In the upper left corner you will find the connection shortcuts to connect to the Scope, PSG, Spectrum Analyzer and the AWG demo board. - Make sure the M8190A firmware is running on the embedded PC. (Start Agilent M8190A M8190). The firmware window can be minimized. [In case you are using your own PC, please see the instructions in the Agilent Arbitrary Waveform Generator M8190A-B02 M8190A ] - Start MATLAB (should be an icon on the desktop) The MATLAB startup-script will automatically launch the MATLAB example main window:

7 - If it does not start automatically, locate the script iqmain.m, right mouse click and run. (iqmain.m is located in c:\program Files(x86)\Agilent\M8190A\Examples\MATLAB\iqtools) From the iqtools main window, you can launch the Instrument configuration window as well as various waveform creation scripts. In the instrument connection window you need to configure the connection to the spectrum analyzer (if you have one connected). The left hand side (AWG connection) should already be set correctly (Instrument model: M8190A, Connection Type: visa, VISA Address: TCPIP0::localhost::hislip0::INSTR). If you are running the MATLAB tools from your laptop, replace localhost by the IP address of the M9536A embedded PC. Multi-tone signal with flatness calibration As a first demonstration signal, you can click on the Multi-Tone Signal & Flatness Correction button, which opens the Multi-tone window: The default settings in this window will create a 100-tone multi-tone signal with random phase distribution in the range 20 MHz to 2 GHz. If you would like to look at how this signal looks in theory, press the Display button to see the time-domain and frequency domain representation of the calculated waveform.

8 Now press the Download button in the Multi-Tone window. Now it is time to look at the waveform that has been generated Connect to the Spectrum analyzer and look at the generated signal. Best experience is by using the Remote Desktop connection (shortcut on desktop), but it s also possible to use VNC or LXI for connecting) As a starting point choose a preset with SA setup from the preset in the iqtone_gui, or you probably need to manually adjust the settings of the spectrum analyzer to see the desired spectrum.

9 Without flatness correction, you ll notice the typical sin(x)/x roll-off of the output signal. To compensate for this non-flatness, change the selection box Calibrate using to Spectrum Analyzer and press the Calibrate button. (Make sure that the Apply Correction checkbox is OFF before you perform your initial correction). If your connection to the spectrum analyzer is configured correctly, you will see the center frequency on the spectrum analyzer toggle through the tone frequencies. After it has completed the sweep, you will briefly see a plot with the measured frequency response. The equalization will take approx. 20 seconds for 100 tones. You can use more tones to increase accuracy, but this will also increase the execution time. Once the measurement is complete, the predistorted waveform is automatically downloaded. (Notice the checkbox Apply correction is now checked)

10 The spectrum analyzer should now look like this: The equalization data that has just been measured is automatically stored in a file and can be used for other waveforms as well. You can go back and forth between the corrected and un-corrected waveform by checking or un-checking the Apply Correction checkbox in each of the MATLAB script windows and downloading the waveform again. Flatness correction of I/Q baseband or up-converted signals The flatness correction as described above corrects the frequency response of a single AWG output channel. You can use the same correction mechanism to correct the frequency of an up-converted IF signal. Simply specify the LO frequency in the field Fc (calibration only) and connect the up-converted signal to the spectrum analyzer. The script will take the frequency shift into account and perform the flatness calibration accordingly. The flatness correction also works for I/Q up-converted signal. In this case, you should set your multitone signal that spans from the negative to positive frequencies. Make sure that you use an asymmetric set of frequencies so that images don t fall on top of tones. A good example is the Multi-tone preset +/- 1 GHz, asymm., 101 tones. NPR measurement signals You can change the multi-tone setup to create an NPR (noise-power-ratio) waveform by adding a notch to your multi-tone signal. Simply check the Notch checkbox in the Multi-tone window and set the desired parameters and download the waveform again. For a 100-tone signal up to 2 GHz with the balun on the output, you can expect the notch depth to be around 60 db.

11 CW and 2-tone signals You can also use this utility to generate CW or two-tone signals. Just set the number of tones to 1 or 2 and specify the desired frequencies. Note, that you can use MATLAB expressions all of the fields. To generate for example a two-tone signal with 10 MHz distance between the tones, you can set the start frequency to 100e6-5e6 and the stop frequency to 100e6 + 5e6. Noise signals In order to generate band-limited pseudo-random noise you have to set the # of tones parameter to zero and the start and stop frequency to the lower and upper band limit for your noise signal. For noise, you have to specify the number of samples manually. If you choose a large number of samples, the quality (i.e. the random-ness ) of the noise signal increases, but it also increases the calculation time. A good starting point is about 1 million samples. Similar to the multi-tone signal, you can add a notch to the noise signal. Just turn on the Notch checkbox and specify the notch center, width and depth. You can even specify multiple notches (with the same or different width and depth) by entering a MATLAB expression into the notch center (width/depth) field that evaluates to a vector. E.g. the expression [100e6 200e6 500e6] will generate notches at 100, 200 and 500 MHz. To generate equally spaced notches, you can use expressions such as linspace(100e6, 900e6, 9), which will generate 9 notches equally spaced between 100 and 900 MHz. Flatness correction using the oscilloscope and VSA software If you don t have a spectrum analyzer connected or if you intend to analyze your final signal on the oscilloscope, you can alternatively perform the flatness calibration using the oscilloscope and the VSA software. To perform the flatness calibration using the scope, make sure that the VSA software automatically connects to the oscilloscope. NOTE: If you have launched the VSA software manually, please exit the application now. The MATLAB script only works correctly if VSA is started by the MATLAB script. Now change the Calibrate using popupmenu in the Multi-Tone window to VSA Software and press Calibrate. After about 30 to 40 seconds, the VSA software should come up. The MATLAB script will automatically configure the VSA software to match the multi-tone signal. Once the dialog box Please check input range and press OK to start calibration. appears, verify that you have a correct signal display and press OK. If not, press Cancel and configure VSA to show a correct signal.

12 Creating a digitally modulated signal In the iqtools main window, click on Digital Modulations (single & multi carrier). This brings up another window that lets you specify the parameters for a digital modulation signal. The parameter Carrier Offset determines if an I/Q baseband signal (Carrier Offset = 0) or an IF/RF signal is generated (Carrier Offset > 0). If you take the default parameters, a 1 GSym/s QAM16 signal will be generated at a 2 GHz IF frequency. If desired, you can use the Display button to look at the theoretical time-domain and frequency domain signal. After you click Download, the spectrum analyzer screen should look similar to the following: In order to look at the demodulated signal, you need to capture the signal using the scope and demodulate it using the VSA software. If you previously launched the VSA software manually, please exit the application now. The MATLAB script only works correctly if VSA is started by the MATLAB script. However, if the VSA software was previously started by one of the MATLAB scripts, the same instance will be re-used. Amplitude and Phase corrections for Digital modulation waveforms When generating a digitally modulated signal with the Digital modulations utility, you can significantly improve the EVM (Error Vector Magnitude) by performing an amplitude and phase calibration in conjunction with the VSA software. The VSA software has to be installed on the same PC that runs the MATLAB scripts. The connection to the oscilloscope that captures the signal has to be established before using the calibration function in the MATLAB script. The calibration routine uses the equalizer that is built into the VSA software to determine the channel frequency response. The MATLAB script uses the

13 complex frequency response of the equalizer to calculate a pre-distorted waveform. Unlike the flatness correction using multi-tone, this method corrects magnitude and phase of the signal. To launch the VSA software from the MATLAB script, press the Calibrate (VSA) button in the Digital Modulations window. The Calibrate function will configure the VSA software with the modulation parameters you have selected in your Digital Modulation window and turn on the built-in equalizer to determine the frequency response of the channel. (Even if you don t need the magnitude/phase calibration, this is a convenient way to set up the VSA software with the desired parameters.) Once the dialog box Please check input range and press OK to start calibration. appears, verify that you have a correct signal display, check the Input Range of the signal and press OK. If you don t want to perform the calibration, simply press Cancel at this point. After you press OK, the MATLAB script will read back the frequency response from the VSA software and use it to download a predistorted signal into the AWG and turn off the equalizer. For a 1 GHz wide QAM16 signal you can expect an EVM less than 1% using this method. Note: If you are working with the I/Q baseband setup, it is important that you adjust the relative amplitude, offset and skew of the two channels before generating the digital modulation signal. Currently, this adjustment has to be done manually. We are working on an automated calibration procedure.

14 Creating a LFM chirp radar pulse signal To create a radar pulse, select Radar Pulses with Frequency Chirps In the iqmain window. This brings up another window that lets you specify the parameters for the pulse. To start with, use the default parameters and check the Apply correction checkbox to use the flatness correction that has been established with the multi-tone signal in the multi-tone demo. Then click Download in the iqpulse window. The spectrum analyzer should show the following: Just like in the previous example, the VSA software can be used to display this wideband chirp. Recall the setup called chirp2ghz2ghz.set or RadarChirp_2GHz_2e-6sec. With that, you should see a screen similar to this one on the scope. Feel free to change the parameters and experiment with the setup.

15 Generating Serial Data signals The Serial Data Generation button in the main window opens a script that allows you to generate distorted serial data patterns. The maximum data rate you can achieve is about ¼ of the sample rate. This is due to the fact that the signal must be oversampled about 4 times to generate the distortions with reasonable accuracy. Another limitation is typically the analog bandwidth of the AWG. The tool allows you to generate 2-level random and clock patterns as well as multi-level and user-defined patterns. You can set the data rate, the transition time, sinusoidal jitter, random jitter, ISI and noise. Similar to the other tools, you can use the Display button to visualize the generated waveform in MATLAB. (Note that the jitter analysis tool currently does not work for multilevel signals). On the oscilloscope, it is best to use the Jitter Analysis or Serial Data Analysis functions to visualize the generated waveform. In order to generate a clean timedomain signal, it is strongly recommended to use an external reconstruction filter on the AWG output with a cutoff frequency below fs/2.

16 4.) Troubleshooting Logins and Passwords Remote Demo PC Login: CZC110BXPK\Instrument, passwd: M8190A4u Spectrum Analyzer: Click on Spectrum Analyzer button, login: Instrument, passwd: measure4u Scope: Click on VNC scope button Errors on remote demo PC In case you get the following error message e.g. when trying to download a waveform to the M8190A AWG, check connection to M8190A, or start/restart M8190A firmware. Front panel of M8190A The steady green Access LED indicates that a PCIExpress link has been established with the AWG module. If the green light is OFF after the embedded PC has booted, the communication to the AWG module is not working. Try re-booting the system. Whenever you download a waveform or send a command to the M8190A, the green access light should briefly blink and go back to steady ON. The red Fail LED has following functionality It is on for about 30 seconds after powering the AXIe chassis

17 During normal operation of the module the LED is OFF unless there is an error condition such as a self test error. In this case the red LED is on. Rebooting of the entire setup helps sometimes. Connection to remote demo PC In case you have problems connecting to the remote demo PCs. There are two possibilities to connect the hardware: - Directly connect to the AWG, Scope and Spectrum Analyzer via VNC. - Connect to the computer xy, start remote desktop connections to the instruments and start a webex session on the computer. This setup has two advantages: o The remote desktop connection on the Spectrum analyzer is faster compared to VNC o You can start a webex session on the computer, and even give your customers control over the instruments via webex. Equipment Control remote demo setup VNC or remote desktop DSO GHz Scope embedded PC M9536A: or Remote Demo PC: CZC110BXPK or N9020A MXA Spectrum Analyzer Instrument measure4u AWG M8190A