MOGlabs QRF041, Manual

Page 1: ...Quad RF Synthesizer QRF041 QRF241 Version 0 2 0 Rev 2 hardware ...

Page 2: ...uential damages in connections with or arising out of the performance or use of any of its products The foregoing limitation of liability shall be equally applicable to any service provided by MOGLabs Copyright Copyright c MOG Laboratories Pty Ltd MOGLabs 2015 2020 No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mecha...

Page 3: ...each channel with 70 kHz bandwidth ergonomic front panel controls and ethernet USB interface The included table mode allows generation of predefined time dependent waveforms The QRF is is single small half rack width box which connects directly to AC mains power As you delve into this manual you will uncover more and more capa bility but the microcontroller at the heart of the QRF allows software ...

Page 4: ...ii ...

Page 5: ...ety precautions that are standard for any electronic equipment CAUTION To ensure correct cooling airflow the unit should not be ope rated with cover removed WARNING High voltages are exposed internally particularly around the mains power inlet and internal power supply unit The unit should not be operated with cover removed NOTE The MOGLabs QRF is designed for use in scientific research laboratori...

Page 6: ...ch RF output should be connected to a 50 Ω load where possible The high power output can tolerate open circuit but should not be short circuited Mains filter Protection against mains transients Temperature Several temperature sensors control the fan and will trigger a shutdown if the temperature exceeds a safe limit iv ...

Page 7: ...es not fall under the scope defined in RoHS Directive 2002 95 EC and is not subject to compliance in accordance with DIRECTIVE 2002 95 EC Out of Scope Electro nics related Intended application is for Monitoring and Control or Medical Instrumentation MOG Laboratories Pty Ltd makes no claims or inferences of the compliance status of its products if used other than for their intended purpose v ...

Page 8: ... Connections and controls 5 2 1 Front panel controls 5 2 2 Menu system 6 2 3 Rear panel controls and connections 8 2 4 Internal DIP switches 9 3 MOGRF host software 11 3 1 Device discovery 11 3 2 Device commander 12 3 3 MOGRF main window 13 4 External modulation 17 4 1 Operational principle 17 4 2 Modulation gain 18 4 3 Dual modulation 18 4 4 PID stabilisation 21 4 5 TTL switching 23 vi ...

Page 9: ... mogrf 31 B 2 Factory reset 32 C Command language 35 C 1 Arguments 35 C 2 General functions 36 C 3 Basic control 36 C 4 Primary RF control 37 C 5 Modulation 38 C 6 Clock reference 39 C 7 Table mode 40 C 8 PID feedback 42 C 9 Ethernet settings 43 D Communications 45 D 1 Protocol 45 D 2 TCP IP 45 D 3 USB 46 E Code examples 49 E 1 python 49 E 2 matlab 50 E 3 LabVIEW 51 ...

Page 10: ...viii Contents ...

Page 11: ...re nominally 50 Ω loads Under no circumstances should the RF output be short circuited 6 Switch on output using the LHS front panel push buttons Chan nels without attached loads should not be enabled 7 Modulation inputs can be used to control the RF with an ana log signal chapter 4 Each channel has an associated SMA input that accepts 1 V 8 External control of the signal is achieved with TTL SMA i...

Page 12: ...x Getting started ...

Page 13: ...uences with fast transitions The block diagram below shows the key components A microcon troller programs the DDS which generates RF output that is low pass filtered pre amplified and then further amplified with a custom GaN hybrid high power output stage QRF241 only The microcontroller provides a front panel display with rotary en coders knobs and push buttons as well as external interfaces over ...

Page 14: ...ommands can be very basic for ex ample to define the frequency or power or they can define complex dynamic sequences Appendix C provides a summary of the available commands 1 1 Operating modes The QRF can be used at varying levels of complexity as either a free running RF source or to follow pre determined instructions defined in a table The modes of operation are outlined below and the current op...

Page 15: ... entries are defined by simple text commands from the host computer which define the RF frequency amplitude phase as detailed in chapter 5 The minimum duration of a TSB entry is 5 µs and each table can comprise up to 8191 instructions 1 2 Feature compatibility The QRF provides a wide range of functionality but not all features are compatible with each other The following table summarises which fea...

Page 16: ...4 Chapter 1 Introduction ...

Page 17: ...ive menu system for displaying the device state and controlling its settings Each channel has an individual on off button on the left hand side and an associated multicolour status LED that indicates the current output state of the channel as shown in the following table Colour DDS active Amplifiers Off 7 7 Green 3 3 Yellow 3 7 Blue 7 3 Purple Debug mode Red Error state 5 ...

Page 18: ...coder wheel is used to edit values The and keys change between menu items exits to the previous menu and OK enters the selected menu or activates the selected command Figure 2 2 The main menu shows the current state of each channel CH1 and CH2 are in table mode with the number of entries in the table shown CH3 and CH4 are in basic mode Figure 2 3 The basic parameters of each channel can be edited ...

Page 19: ...mode the currently selected digit is shown on a black background and is changed by turning the encoder wheel Pressing the encoder again returns to value modification mode The options menu Figure 2 4 allows the device configuration to be adjusted such as the power limit of each channel see also the LIM command The ethernet settings of the device can also be set using this interface including the st...

Page 20: ... Australia Figure 2 5 QRF rear panel layout IEC power in The QRF is compatible with all standard AC power systems from 90 to 264 V and 47 to 63 Hz Fan The QRF has five temperature controlled fans directing air flow over the RF power amplifiers exhausting through the rear vent Ensure that the vent does not become blocked RF SMA connectors for the primary RF outputs Nominally connected to a 50Ω load...

Page 21: ...ssist in diagnosis and recovery of the QRF units They should all be left in default configuration set to OFF for regular operation WARNING There is potential for exposure to high voltages inside the QRF Take care around the power supply and ensure that objects particularly electrically conducting objects do not enter the unit CAUTION The cover should be replaced before powering on to ensure proper...

Page 22: ...10 Chapter 2 Connections and controls ...

Page 23: ...Device discovery Upon starting the application a device discoverer Figure 3 1 is initiated This program scans the COM ports of the host computer looking for a QRF device and then scans the local network subnet Starting the application is then as simple as selecting the device and clicking Connect If your device is not listed recheck your connection and network settings If the network and or firewa...

Page 24: ...executed commands Figure 3 2 The Device commander window which permits the execution of individual instructions or of text files containing scripts Scripts are ASCII text files where each line corresponds to a com mand to be executed see Appendix E Clicking Run script triggers stepwise execution of such a script where the success of each sta tement is checked before executing the subsequent line I...

Page 25: ...nd CH3 and CH4 are in table mode Different options are presented in different operating modes Each channel is controlled individually as follows The operational mode of the channel can be changed by clicking on the coloured box In basic mode the frequency amplitude and phase are dis played Changing the value immediately updates the output In table mode buttons are provided to trigger specific func...

Page 26: ...ful for configuring the network settings over USB Note that changing the Static IP only has an effect if DHCP is disabled or if DHCP name resolution fails Figure 3 4 Ethernet configuration interface Note that changing the ethernet settings will require the application to be restarted and may also require the device to be rebooted The port should be unchanged at 7802 to ensure that the mogrf suite ...

Page 27: ...channel can have a primary and secondary modulation enabled 4 3 which use the associated physical modulation input mapping The gain can be set using the slider or by entering a value directly Negative gain is specified by ticking the Invert check box Similarly PID can be enabled on the primary channel 4 4 and the gains adjusted in the same way ...

Page 28: ...16 Chapter 3 MOGRF host software ...

Page 29: ...ing word for frequency amplitude scale factor for power or phase offset word for phase Limits are applied to ensure that the value remains within the bounds The ADC has 12 bit resolution 1 V range has 2nd order anti aliasing filters at 100 kHz and a measured 3 dB bandwidth of 70 kHz Modulation is enabled disabled with the MOD command1 For exam ple to enable AM on channel 1 use the command MOD 1 AM...

Page 30: ...nted as a percentage of full scale am plitude Therefore a gain of 100 will bring the output to full power at 1 V input as restricted by the channel s power LIMIT To pre vent unexpected results it is recommended to verify the modulation gain by disconnecting the load and checking the amplitude of the RF output on an oscilloscope with 50Ω termination 4 3 Dual modulation The QRF supports dedicating t...

Page 31: ...nfigured the primary and secondary modulation inputs can then be activated using the MOD command as shown in the example below this example shows dual modulation on CH1 we configure the MOD1 input for FM and MOD2 for AM MAPMOD 1 1 2 MOD 1 FM AM configure the modulation gains GAIN 1 FM 10 MHz 10 MHz V GAIN 1 AM 10 10 of full scale amplitude Listing 4 1 Demonstration of simultaneous AM FM on CH1 Fig...

Page 32: ...sed for FM and AM respecti vely mapmod 1 1 ACTIVE 2 ACTIVE mod 1 FM AM Listing 4 2 Example verifying the modulation configuration of CH1 There are several restrictions in dual modulation mode Simultaneous modulation of a single parameter is not permit ted e g two inputs both controlling FM of one channel Mapping a second modulation input to the same modulation mode will override the first e g atte...

Page 33: ...oop Upon activating the PID controller the channel s modulation input is treated as an error signal instead of a control voltage and the action of the controller is to drive this signal towards zero Locking to a non zero value can be achieved with the PID SETPOINT command However to make best use of the analog to digital converter s dyn amic range it is recommended to remove the set point before d...

Page 34: ...rd PID function u t Gkpe t Gki Z t 0 e τ dτ Gkd de dt where e t is the input error signal u t is the feedback response and G is the overall modulation gain The gain constants kp ki kd are floating point values in the range 0 1 which tune the proporti onal integral and differential responses respectively Typical values depend on the application but reasonable starting values are often kp 0 1 ki 0 0...

Page 35: ...Example of pulse generation using the ON OFF input showing a response time of 40 ns Red is the TTL signal blue is the RF signal Each channel has one TTL input on the rear panel labelled ON OFF In basic NSB mode pulling the TTL LOW will rapidly disable the RF switch and returning it HIGH will reenable the switch In table mode it is used as a hardware trigger for synchronising the table execution No...

Page 36: ...24 Chapter 4 External modulation ...

Page 37: ... TTL trigger on the channel s ON OFF input or using the TABLE START command The table can be automatically restarted after completion by enabling the TABLE RESTART option and execution can be stopped mid sequence using the TABLE STOP command When a table is armed the RF is switched on and upon completion of the table the final RF state remains ongoing If it is required that the output be disabled ...

Page 38: ...le table mode commands Figure 5 1 Output waveform generated by simple table mode example Typically more complicated pulse sequences are of interest such as generated shaped envelopes with frequency sweeps These tables are often generated by user created scripts or as part of a control system An example of such a pulse is shown in Figure 5 2 where the RF frequency is swept under a Gaussian envelope...

Page 39: ... After a table is armed with the TABLE ARM command it will automa tically begin executing upon a falling external trigger on the asso ciated channel s TTL input It is therefore typically not necessary to use the TRIG flag on the first table entry for such operation If a trigger is not received the TABLE STOP command should be used to abort operation 5 3 Re arm and restart The QRF can be instructed...

Page 40: ...able can be repeated continuously by enabling the TABLE RESTART option This will cause the table to immediately re execute after it has been rearmed although an initial hardware or software trigger must be provided to begin the first execution ...

Page 41: ...ol 32 bit resolution 0 116 Hz steps Frequency stability 25 ppm 0 to 50 C Phase 0 to 2π 14 bit resolution Phase noise TBD Signal to noise TBD Intermodulation and spurious TBD Channel crosstalk 70 dBc off 50 dBc on Power on RF off 70 dBm Analogue input Inputs 1 per channel 4 total Function FM AM φ or PID Sensitivity 1 V Bandwidth 70 kHz with 2nd order anti alias Resolution 12 bit Input impedance 5 k...

Page 42: ... 6 V Absolute max in 6 5 V Absolute min in 0 5 V Table mode Min step size 5 µs Max table length 8191 instructions per channel Trigger options Software or TTL via rear panel Channel sync Configurable independent or synchronised Mechanical power Display 320x240 px colour LCD Fans 5 x temperature controlled fans IEC input 90 to 264 Vac 47 to 63 Hz Dimensions W H D 250 79 292 mm Weight 2 kg ...

Page 43: ...ut the current firmware will be shown and you will be given the option to install an update Figure B 1 Note that the device should not be used while upgrading firmware Figure B 1 The firmware update application connected to a unit showing the device information top and current firmware versions middle Ensure that the model numbers are correct before continuing Update packages are available from th...

Page 44: ... FLASH memory is erased to make room for the new image 2 The data is uploaded to the device 3 The device checks the data is received for consistency to en sure the upload was successful 4 The device is rebooted to load the new firmware The device will reboot after every individual component upgrade to ensure the upload was successful before moving on to the next component The software will automat...

Page 45: ...ngs power limits frequencies calibrations and so on Ensure that relevant values are corrected after the reset Once the reset is complete upgrade can be reattempted to gain access to newer features or a different firmware can be applied Please contact MOGLabs if you encounter any difficulties during firmware upgrade ...

Page 46: ...34 Appendix B Firmware upgrades ...

Page 47: ...propriate namely Frequency Hz kHz MHz default Power dBm default dB mW W Phase deg default rad Time ns us default ms s Note that when requesting a particular value to change the actual value may differ from the requested value because of discretisation and or parameter limits Typically the command will respond with the closest permitted value If required values corresponding to internal representat...

Page 48: ...s are switched on Returns an error if the device is not operational MODE MODE ch type Controls the operational mode of the given channel type is one of NSB NSA or TSB see 1 1 Note that some options are only available in particular modes Note this command automatically switches off the output of the specified channel OFF ON OFF ch mode ON ch mode Enable or disable the RF output of the specified cha...

Page 49: ...he maximum RF power for given channel ch with the same syntax as the POW command If the limit is set below the current power level the current power is reduced to the limit PHASE PHASE ch phase Set channel ch to have the specified phase offset ALIGNPHASE ALIGNPH ch ch Simultaneously resets the phase accumulators of the associated channels This may be necessary to re establish a stable phase relati...

Page 50: ...mary and secondary modes 4 3 Alternatively the primary and secondary modes can be configured separately by specifying PRI or SEC GAIN GAIN ch type gain Sets the modulation gain for the specified modulation type on the given channel gain is a floating point number with units or a signed hexadecimal integer that controls the depth of the modulation 4 2 If gain is negative then the modulation action ...

Page 51: ...e source is either INT to use the internal 25 MHz oscillator or EXT to use the reference provided to the CLK IN connector When using EXT mode the parameter freq must be the frequency in MHz An error will be generated if the clock frequency is not supported Specifying the freq as either zero or 500 will disable the DDS s PLL and it will clock directly from the provided signal Configuring an externa...

Page 52: ...ry to edit 1 to 8191 freq Frequency to output during this step pow Output power during this step phas Phase offset of the RF for this step dur Duration of this step discretised at 5 us If zero the entry is held until a hardware trigger is received HEXENTRY TABLE HEXENTRY ch num Queries the specified table entry returning the internal hexadecimal representation of the associated frequency amplitude...

Page 53: ...hannels can be specified to arm them simultaneously START TABLE START ch Provides a software trigger to initiate table execution Multiple channels can be specified to start them simultaneously STOP TABLE STOP ch Terminates an executing table at the end of the current step Mul tiple channels can be specified to stop them simultaneously REARM TABLE REARM ch on off Enables disables the automatic re a...

Page 54: ...Applies a DC offset to enable locking to a non zero set point voltage If specified the voltage val must be between 1 and 1 V Note that the lock may become unstable close to these limits due to clipping of the error signal INVERT PID INVERT ch on off Inverts the controller action for the given channel GAIN PID GAIN ch name value Sets the PID gain constant for name which is one of P proportional I i...

Page 55: ...STATIC ETH STATIC ipaddr Set IP address based on the supplied dotted quad string for example 10 1 1 180 The static address is used if DHCP fails or is disabled MASK ETH MASK ipmask Set IP mask based on dotted quad string for example 255 255 255 0 GW ETH GW ipaddr Set IP gateway based on dotted quad string for example 10 1 1 1 PORT ETH PORT port Set the TCPIP port number for device communication DH...

Page 56: ...44 Appendix C Command language ...

Page 57: ...depending on whether the action succeeded It is strongly recommended that all software should wait for this response and check for success before continuing The python and LabVIEW bindings provided take care of buffering and error checking automatically The MOGLabs Device Commander application is available as part of the mogrf package and provides a convenient interface for sending commands and re...

Page 58: ...t Restart ethernet and press the OK button 6 The new IP address will be displayed in the display footer In some situations it may be necessary to power cycle the device to propagate ethernet changes D 3 USB The QRF can be directly connected to a host computer using a USB cable type A male The device will appear as a Virtual COM port which behaves like an RS232 connection The required STM32 Virtual...

Page 59: ...n be identified as a COM port with the following name STMicroelectronics Virtual COM Port COMxx where xx is a number typically between 4 and 15 In the example above the device was installed as COM4 Note that if the port appears in Device Manager with a different name then the driver was not successfully installed If this occurs disconnect the device from the host computer reinstall the VCP driver ...

Page 60: ...48 Appendix D Communications ...

Page 61: ...ueries The follo wing example shows how to construct a Gaussian pulse using numpy and the MOGDevice class with the resulting waveform shown in Fi gure E 1 Gaussian pulse example c MOGLabs 2020 from mogdevice import MOGDevice import numpy as np connect to the device dev MOGDevice 192 168 1 20 construct the pulse N 250 number of points to generate X np linspace 1 1 N P 5 35 X 2 Gaussian amplitude 30...

Page 62: ...matlab The listing below demon strates how to generate the previous example in matlab MATLAB pulse example c MOGLabs 2020 create a device instance dev mogdevice example connecting by ethernet dev connect 10 1 1 31 print some information about the device disp dev ask INFO create a gaussian envelope N 250 X 1 N N 2 1 P 5 35 X 2 F 100 50 X upload gaussian pulse in simple table mode dev cmd MODE 1 TSB...

Page 63: ...rface over both ethernet and USB They perform automatic error checking and are compatible with LabVIEW 2009 and later editions Figure E 2 Example LabVIEW program that connects to an QRF unit and performs a number of queries When using these drivers it is strongly recommended that the au tomatic session close option be enabled to prevent communications problems if the VI aborts or is interrupted Th...

Page 64: ...aboratories Pty Ltd 49 University St Carlton VIC 3053 Australia Tel 61 3 9939 0677 info moglabs com c 2015 2020 Product specifications and descriptions in this do cument are subject to change without notice ...