Silicon Radar SiRad Simple User Manual Download Page 28

 

 

 

 
User Guide (Version 2.2) of the 
SiRad Simple® Evaluation Kit 

- 28 - 

4.2.14 

There are too many targets. The CFAR operator does not work. 

You may experience that there are no targets detected by the CFAR operator although there are 
plenty of targets visible in the FFT output. If there are too many targets adjacent to each other in 
the  field  of  view,  the  CFAR  operator  may  treat  those  targets  like  noise  floor  and  calculates  an 
envelope around those targets. Increasing the number of guard cells may help in such a scenario. 
 

4.2.15 

How is the distance information calculated? 

All calculations are done on the microcontroller on the SiRad Simple® sensor, so that the reported 
target distance is already in millimeters. The distance formula used is  

d = n

Bin

 * acc, 

where d is the distance to the target, n

Bin

 is the FFT bin of the target, and acc is the accuracy (see 

Section 3.3.2 for the formula). 
 

4.2.16 

The update rate of the sensor is very low. How can I improve it? 

The update rate is dependent on the chosen parameters in the ‘BB Processing’ tab, in particular, on 
the ramp time, number of samples,  number of ramps,  and FFT size. Further, the amount of data 
that  has  to  be  transferred  is  important.  You  can  select  the  transmitted  frames  in  the  ‘System 
Configuration’ tab. Using only the target list output, the sensor can reach about 50 Hz update rate. 
 

4.3  Sensor Behavior, Range & Lens 

 

4.3.1 How is the resolution defined? 

We  define  the  resolution  as  the  ability  to  separate  two  targets  in  range.  The  resolution  is  only 
dependent  on  the  selected  bandwidth.  With  1 GHz  bandwidth  the  resolution  is  15 cm,  6 GHz 
bandwidth equals 2.5 cm resolution. In practice, target recognition works from twice the resolution. 
 

4.3.2 How is the accuracy defined? 

We  define  accuracy  as  the  maximum  error  of  the  measured  distance  to  a  single  target.  It  is 
dependent on the number of samples, the bandwidth, the downsampling and the FFT size. If the 
FFT size is twice the number of samples, the accuracy is two times less than the resolution. We 
can reach about 1 mm accuracy, also see Section 3.3.2 for the formula. 
 

4.3.3 Is there a minimum range / blind spot when using the SiRad Simple®? 

The  minimum  range  depends  on  the  selected  bandwidth.  1 GHz  bandwidth  works  from  about 
30cm, 6 GHz bandwidth works from about 7cm. The blind spot is approximately as wide as once or 
twice the resolution. 
 

4.3.4 Can something be detected within the minimum range / blind spot? 

Going  below  the  bandwidth-dictated  minimum  range  leads  to  an  increased  DC-offset  in  the  FFT 
output. It could be used to detect ‘something is nearby’ but this is very application-specific. 
 

4.3.5 What is the maximum range of the SiRad Simple®? 

The maximum range is dependent on the target. The SiRad Simple® Evaluation Kit reaches about 
40 m with strong targets like buildings. 
 

4.3.6 Can the range of the sensor be increased? 

You can increase the range by assembling the lens delivered with the SiRad Simple® Evaluation 
Kit, however, the opening angle will decrease. Larger detection distances are possible using bigger 
lenses or well-designed patch array antennas. 

Summary of Contents for SiRad Simple

Page 1: ...se 24 Apr 17 Silicon Radar GmbH Version Document number Filename Page 2 2 UserGuide_SiRad_Simple 1 of 34 Silicon Radar GmbH Im Technologiepark 1 15236 Frankfurt Oder Germany fon 49 335 557 17 60 fax 4...

Page 2: ...2 2 3 Connecting to the Board via WiFi 11 2 2 4 Starting the Graphical User Interface Silicon Radar WebGUI 11 3 Getting Started with the Silicon Radar WebGUI 12 3 1 Understanding the User Interface 1...

Page 3: ...s the MTI Mode 27 4 2 14 There are too many targets The CFAR operator does not work 28 4 2 15 How is the distance information calculated 28 4 2 16 The update rate of the sensor is very low How can I i...

Page 4: ...ntrol Panel 14 Figure 14 System Configuration tab of the Control Panel 14 Figure 15 RF Parameters tab of the Control Panel 16 Figure 16 BB Processing tab of the Control Panel 17 Figure 17 Target Recog...

Page 5: ...Figure 1 right Figure 1 SiRad Simple Evaluation Kit left and graphical user interface right The SiRad Simple Evaluation Kit demonstrates the performance and parameters of the 122 GHz radar transceive...

Page 6: ...the I and Q output signals of the transceiver Analog to Digital converter to digitize the I and Q receiver signals microcontroller to do PLL setup ramp configuration A D conversion signal processing...

Page 7: ...R also see Section 3 2 3 1 Pin Description 5V 5V GD GND MT microcontroller TX MR microcontroller RX TR external trigger line WT WiFi TX WR WiFi RX 3 3V tolerant only Figure 2 External header J1 pinout...

Page 8: ...mper J2 for the WiFi module switched on and connect two jumpers between MT WR and MR WT Apply 5V to the 5V pin and GND to the any GD pin there are four of the external header J1 Figure 4 WiFi pinout o...

Page 9: ...ined in Section 2 1 2 UART and 2 1 3 WiFi Please configure the sensor board for either the UART mode for the USB connection or the WiFi mode before proceeding to one of the next sections The Evaluatio...

Page 10: ...ion of the software you can now optionally connect to this serial port using a terminal program such as PuTTY6 or Realterm7 with the following UART settings 230400 baud 8 bits 1 stop bit no flow contr...

Page 11: ...n Windows the IP address that was assigned by the sensor s WiFi module to your PC can be checked in the network manager Proceed to Section 2 2 4 for running the graphical user interface 2 2 4 Starting...

Page 12: ...the screen with the active view in orange scene canvas itself where the sensor data is displayed target list with the status fields on the right side of the screen draggable The control buttons on th...

Page 13: ...lhost 9090 is for communication via the USB port see Figure 11 left If you are using WiFi type in the IP address and the port 9090 of the sensor s WiFi module like in Figure 11 right for example 192 1...

Page 14: ...e 12 right those will be automatically restored next time you open the browser 3 2 3 System Settings System Configuration Tab The System Configuration tab shown in Figure 14 is used to control the kin...

Page 15: ...s DC cancellation activates the DC offset compensation of the ADC data Range data activates the transmission of the distance data frames which contain the distance spectrum data in dB for each distanc...

Page 16: ...4 Radar Frontend Settings RF Parameters Tab The RF Parameters tab in Figure 15 is used to control the radar frontend of the sensor For each radar measurement the frontend is driven with one or more fr...

Page 17: ...ramps The bandwidth should not exceed the maximum frequency fmax of the frontend minus the minimum frequency fmin of the frontend minus 200 MHz Base frequency set the start frequency of the frequency...

Page 18: ...R Hence higher values give slower measurements but better SNR However too many ramps may smear out the signal due to the phase noise of the system Downsampling determines how many samples are averaged...

Page 19: ...tion Description 0 3 Reserved 4 bins number of the distance bin which receives the data 5 mm data is displayed in mm depending on the accuracy 6 cm data is displayed in cm depending on the accuracy Fi...

Page 20: ...Protocol Description for further information about the sensor s communication protocol 3 3 Using the Main Menu The main menu is shown in Figure 21 Here you can select how the data should be displayed...

Page 21: ...ate from the TSLM value time since last measurement The Target list shown in Figure 24 bottom part is ordered by distance With every new measurement having the CFAR operator enabled the Target list is...

Page 22: ...e Options menu you can choose the coloring of the data between Magnitude Range target number Phase angles the phase angles are only colorized if the magnitude is larger than 120 dB and when the Phase...

Page 23: ...of the view relative to the specified axis The camera view can be changed using the mouse within the scene area A left click drag pans the camera position A right click drag changes the camera view a...

Page 24: ...uring processing but do not last longer than 3 times checking them The temporary error flags are removed automatically Persistent errors are errors that last longer than 3 times checking them and can...

Page 25: ...daptive nature of the CFAR operator it might happen that if two targets are too near to each other or are very different in magnitude one of them is rejected hidden by the CFAR operator such a target...

Page 26: ...ion 2 2 2 4 2 WebGUI 4 2 1 I cannot store presets in the Preset tab Please make sure you are not working in the private mode of your browser and you have enabled cookies since the presets are stored a...

Page 27: ...tab does not show the min max frequencies properly You can try a manual min max frequency scan by clicking the fscan button three times 4 2 9 How do I choose a base frequency The base frequency shoul...

Page 28: ...ability to separate two targets in range The resolution is only dependent on the selected bandwidth With 1 GHz bandwidth the resolution is 15 cm 6 GHz bandwidth equals 2 5 cm resolution In practice ta...

Page 29: ...l the sensor with your own software or third party software like MATLAB 4 4 2 Can I activate raw data only or FFT data only output Yes Please read the Protocol Description about how to set up the sens...

Page 30: ...ll Package into the stm32flash folder Edit the batch file stm32flash bat and replace the COM port with the COM port of your USB to UART cable and the firmware name with the desired firmware marked her...

Page 31: ...Edit the batch file esptool bat and replace the COM port with the COM port of your USB to UART cable and the firmware name with the desired firmware marked here esptool bz 1M cp COMx cf websocket_mini...

Page 32: ...User Guide Version 2 2 of the SiRad Simple Evaluation Kit 32 6 Mechanical Drawing Figure 37 Mechanical drawing of the SiRad Simple Evaluation Kit...

Page 33: ...the critical uses policy set forth below CRITICAL USE EXCLUSION POLICY BUYER AGREES NOT TO USE SILICON RADAR GMBH S PRODUCTS FOR ANY APPLICATION OR IN ANY COMPONENTS USED IN LIFE SUPPORT DEVICES OR T...

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