Difference between pages "A-C4E10 Cyclone IV FPGA EP4CE10E22C8N Development Board" and "RF Attenuators"

From Land Boards Wiki
(Difference between pages)
Jump to navigation Jump to search
 
 
Line 1: Line 1:
−
[[File:Card_002_Rotated_transformed.PNG]]
+
== Homebrew RF Attenuators ==
  
−
== Features ==
+
[[file:Atten_30dB_20dV_P1812-720px.jpg]]
  
−
* [https://www.ebay.com/itm/Intel-Altera-Cyclone-IV-FPGA-development-board-EP4CE10E22C8N-with-VGA-port/362877625504?hash=item547d3124a0:g:x-kAAOSwnVVZoVGW Ebay listing]
+
== Attenuators ==
  
−
== Pin List ==
+
[[file:Chart_mW_vs_dbM.PNG]]
  
−
<pre>
+
=== 30 dB Attenuator ===
−
set_location_assignment PIN_6 -to ~ALTERA_ASDO_DATA1~
+
 
−
set_location_assignment PIN_8 -to ~ALTERA_FLASH_nCE_nCSO~
+
* [http://leleivre.com/rf_pipad.html Pi Attenuator Calculator]
−
set_location_assignment PIN_12 -to ~ALTERA_DCLK~
+
 
−
#
+
[[file:Atten30dB_P116-720px.jpg]]
−
set_location_assignment PIN_113 -to i_rxd
+
 
−
set_location_assignment PIN_114 -to o_txd
+
[[file:30dB_Attenuator.PNG]]
−
set_location_assignment PIN_86 -to i_n_reset
+
 
−
set_location_assignment PIN_23 -to i_clk
+
* Built
−
set_location_assignment PIN_11 -to i_ps2Clk
+
** Standard 5% resistor values
−
set_location_assignment PIN_10 -to i_ps2Data
+
** R1 = 820 in parallel with 22K = 790.6 ohms
−
# Seven Segment LEDs
+
** R2 = 2 paralleled 120 Ohm 1/4W resistors paralleled with 470 ohms = 53.2 ohms
−
set_location_assignment PIN_127 -to o_LED7Seg_out[0]
+
** Flat from 0-30 MHz
−
set_location_assignment PIN_126 -to o_LED7Seg_out[1]
+
** Measured attenuation is flat
−
set_location_assignment PIN_125 -to o_LED7Seg_out[2]
+
*** -30.01dB at 1 MHz
−
set_location_assignment PIN_124 -to o_LED7Seg_out[3]
+
*** -30.24dB at 30 MHz
−
set_location_assignment PIN_121 -to o_LED7Seg_out[4]
+
** Input Impedance - 53.1 ohms, 21.3nF
−
set_location_assignment PIN_120 -to o_LED7Seg_out[5]
+
** SWR 1.06
−
set_location_assignment PIN_119 -to o_LED7Seg_out[6]
+
** 1/2W max (5VDC max, 0 ohm source)
−
set_location_assignment PIN_115 -to o_LED7Seg_out[7]
+
 
−
set_location_assignment PIN_128 -to o_Anode_Activate[0]
+
* NanoVNA scan data
−
set_location_assignment PIN_129 -to o_Anode_Activate[1]
+
 
−
set_location_assignment PIN_132 -to o_Anode_Activate[2]
+
[[file:30dB_Attenuator_NanoVNA_Setup_Curve_900MHz.PNG]]
−
set_location_assignment PIN_133 -to o_Anode_Activate[3]
+
 
−
set_location_assignment PIN_135 -to o_Anode_Activate[4]
+
[[file:30dB_Attenuator_NanoVNA_Data_900MHz.PNG]]
−
set_location_assignment PIN_136 -to o_Anode_Activate[5]
+
 
−
set_location_assignment PIN_137 -to o_Anode_Activate[6]
+
* LTSPICE Simulation
−
set_location_assignment PIN_138 -to o_Anode_Activate[7]
+
 
−
# Buzzer
+
[[file:LTSPice_30dB.PNG]]
−
set_location_assignment PIN_141 -to o_BUZZER
+
 
−
# Switches
+
=== 20 dB Attenuator ===
−
set_location_assignment PIN_87 -to i_pbutton[0]
+
 
−
set_location_assignment PIN_91 -to i_pbutton[2]
+
[[file:Atten_20dB_P115-720px.jpg]]
−
set_location_assignment PIN_90 -to i_pbutton[1]
+
 
−
set_location_assignment PIN_58 -to i_DipSw[0]
+
[[file:20dB_Attenuator.PNG]]
−
set_location_assignment PIN_59 -to i_DipSw[1]
+
 
−
set_location_assignment PIN_60 -to i_DipSw[2]
+
* Build
−
set_location_assignment PIN_64 -to i_DipSw[3]
+
** Standard 5% resistor values
−
set_location_assignment PIN_65 -to i_DipSw[4]
+
** R1 = 2 of 510 in parallel also in parallel with 8.2K = 247.3 ohms
−
set_location_assignment PIN_66 -to i_DipSw[5]
+
** R2 = 2 paralleled 150 Ohm 1/2W resistors paralleled with 330 ohms = 61.11 ohms
−
set_location_assignment PIN_67 -to i_DipSw[6]
+
** Flat from 0-30 MHz
−
set_location_assignment PIN_68 -to i_DipSw[7]
+
** Measured attenuation is flat
−
# LEDs
+
** Input Impedance - tbd ohms, tbd nF
−
set_location_assignment PIN_72 -to o_LED[0]
+
** SWR tbd
−
set_location_assignment PIN_73 -to o_LED[1]
+
** 1W max (8.6 V max, 0 ohm source)
−
set_location_assignment PIN_74 -to o_LED[2]
+
 
−
set_location_assignment PIN_80 -to o_LED[3]
+
[[file:20dB_Attenuator_NanoVNA_Setup_Curve_900MHz.PNG]]
−
set_location_assignment PIN_83 -to o_LED[4]
+
 
−
set_location_assignment PIN_84 -to o_LED[5]
+
[[file:20dB_Attenuator_NanoVNA_Data_900MHz.PNG]]
−
set_location_assignment PIN_77 -to o_LED[6]
+
 
−
set_location_assignment PIN_76 -to o_LED[7]
+
* LTSPICE Simulation
−
set_location_assignment PIN_75 -to o_LED[8]
+
 
−
set_location_assignment PIN_71 -to o_LED[9]
+
[[file:LTSPice_20dB.PNG]]
−
set_location_assignment PIN_70 -to o_LED[10]
+
 
−
set_location_assignment PIN_69 -to o_LED[11]
+
=== 10 dB Attenuator ===
−
# Video
+
 
−
set_location_assignment PIN_144 -to o_Vid_Blu
+
[[file:Atten_10dB_P115-720px.jpg]]
−
set_location_assignment PIN_1 -to o_Vid_Grn
+
 
−
set_location_assignment PIN_2 -to o_Vid_Red
+
[[file:10dB_Attenuator.PNG]]
−
set_location_assignment PIN_142 -to o_Vid_hSync
+
 
−
set_location_assignment PIN_143 -to o_Vid_vSync
+
* Build
−
</pre>
+
** Standard 5% resistor values
 +
** R1 = 2 of 150 in parallel also in parallel with 1.5K = 71.43 ohms (0.3% error)
 +
** R2 = 3 of 330 Ohm 1/4W parallel resistors paralleled with 810 ohms = 96.85 ohms (0.62% error)
 +
** Flat from 0-30 MHz
 +
** Measured attenuation is flat
 +
** Input Impedance - tbd ohms, tbd nF
 +
** SWR tbd
 +
** 3/4W max (9.1 V max, 0 ohm source)
 +
 
 +
[[file:10dB_Attenuator_NanoVNA_Setup_Curve_900MHz.PNG]]
 +
 
 +
[[file:10dB_Attenuator_NanoVNA_Data_900MHz.PNG]]
 +
 
 +
* LTSPICE Simulation
 +
 
 +
[[file:LTSPice_10dB.PNG]]
 +
 
 +
=== Attenuator Construction ===
 +
 
 +
* Single side copper clad PCB
 +
** Approx 2"x1"
 +
* Clean with steel wool
 +
* Solder SMA connectors
 +
** Use large alligator clips to hold while soldering
 +
** Solder on sides only
 +
 
 +
[[file:Atten_01_SMAs_720px.jpg]]
 +
 
 +
* Cut "T" Shaped pads
 +
** I used nibbler
 +
* Center fits between connector ground pins
 +
* Glue down pads with Superglue
 +
 
 +
[[file:Atten_02_Pads_720px.jpg]]
 +
 
 +
* Solder center pin with big solder blob
 +
** A bit too high for direct contact
 +
* Verify raised pad does not short to ground
 +
 
 +
[[file:Atten_03_Solder CenterPads_720px.jpg]]
 +
 
 +
* Solder side resistor(s)
 +
* Leave room for center resistor(s)
 +
 
 +
[[file:Atten_04_Solder Side_Resistors_720px.jpg]]
 +
 
 +
* Measure side resistors from pad to ground
 +
* Should match value
 +
* Solder center resistor(s)
 +
 
 +
[[file:Atten_05_Solder Center_Resistors_720px.jpg]]
 +
 
 +
* Verify no shorts between centers and ground
 +
 
 +
== References ==
 +
 
 +
<video type="youtube">A5gGeV7CiQ0</video>

Revision as of 11:50, 7 September 2021

Homebrew RF Attenuators

Atten 30dB 20dV P1812-720px.jpg

Attenuators

Chart mW vs dbM.PNG

30 dB Attenuator

Atten30dB P116-720px.jpg

30dB Attenuator.PNG

  • Built
    • Standard 5% resistor values
    • R1 = 820 in parallel with 22K = 790.6 ohms
    • R2 = 2 paralleled 120 Ohm 1/4W resistors paralleled with 470 ohms = 53.2 ohms
    • Flat from 0-30 MHz
    • Measured attenuation is flat
      • -30.01dB at 1 MHz
      • -30.24dB at 30 MHz
    • Input Impedance - 53.1 ohms, 21.3nF
    • SWR 1.06
    • 1/2W max (5VDC max, 0 ohm source)
  • NanoVNA scan data

30dB Attenuator NanoVNA Setup Curve 900MHz.PNG

30dB Attenuator NanoVNA Data 900MHz.PNG

  • LTSPICE Simulation

LTSPice 30dB.PNG

20 dB Attenuator

Atten 20dB P115-720px.jpg

20dB Attenuator.PNG

  • Build
    • Standard 5% resistor values
    • R1 = 2 of 510 in parallel also in parallel with 8.2K = 247.3 ohms
    • R2 = 2 paralleled 150 Ohm 1/2W resistors paralleled with 330 ohms = 61.11 ohms
    • Flat from 0-30 MHz
    • Measured attenuation is flat
    • Input Impedance - tbd ohms, tbd nF
    • SWR tbd
    • 1W max (8.6 V max, 0 ohm source)

20dB Attenuator NanoVNA Setup Curve 900MHz.PNG

20dB Attenuator NanoVNA Data 900MHz.PNG

  • LTSPICE Simulation

LTSPice 20dB.PNG

10 dB Attenuator

File:Atten 10dB P115-720px.jpg

10dB Attenuator.PNG

  • Build
    • Standard 5% resistor values
    • R1 = 2 of 150 in parallel also in parallel with 1.5K = 71.43 ohms (0.3% error)
    • R2 = 3 of 330 Ohm 1/4W parallel resistors paralleled with 810 ohms = 96.85 ohms (0.62% error)
    • Flat from 0-30 MHz
    • Measured attenuation is flat
    • Input Impedance - tbd ohms, tbd nF
    • SWR tbd
    • 3/4W max (9.1 V max, 0 ohm source)

File:10dB Attenuator NanoVNA Setup Curve 900MHz.PNG

File:10dB Attenuator NanoVNA Data 900MHz.PNG

  • LTSPICE Simulation

LTSPice 10dB.PNG

Attenuator Construction

  • Single side copper clad PCB
    • Approx 2"x1"
  • Clean with steel wool
  • Solder SMA connectors
    • Use large alligator clips to hold while soldering
    • Solder on sides only

Atten 01 SMAs 720px.jpg

  • Cut "T" Shaped pads
    • I used nibbler
  • Center fits between connector ground pins
  • Glue down pads with Superglue

Atten 02 Pads 720px.jpg

  • Solder center pin with big solder blob
    • A bit too high for direct contact
  • Verify raised pad does not short to ground

Atten 03 Solder CenterPads 720px.jpg

  • Solder side resistor(s)
  • Leave room for center resistor(s)

Atten 04 Solder Side Resistors 720px.jpg

  • Measure side resistors from pad to ground
  • Should match value
  • Solder center resistor(s)

Atten 05 Solder Center Resistors 720px.jpg

  • Verify no shorts between centers and ground

References

Retrieved from "http://land-boards.com/blwiki/index.php?title=A-C4E10_Cyclone_IV_FPGA_EP4CE10E22C8N_Development_Board&oldid=8642"