RF-Amp

From Land Boards Wiki
Jump to navigation Jump to search

RF-Amp Front.png

RF Amplifier Features

RF Amplifier Design

Schematic

RF Amp Schematic-4.PNG

DC Operating Point

  • Ice = 10 mA
  • Ve = 0.1 * Vcc = 1.2V

Input/Output Transformer

FT37-43 Toroid

  • FT37-43
  • Wideband Transformers 5 - 400 MHz
  • Power Transformers 0.5 - 30 MHz
  • 10 turns = 35uH

FT37-43 10 Turns.PNG

Tracks

RF-Amp-tracks.PNG

Input Transformer

    • Input Transformer (T1 on Charlie's - T2 on this board)
      • 50:75.8 Ohms = 1 : 1.23 turns ratio
        • 9 turns primary, 11 turns on secondary

RF-Amp-T2.PNG

Output Transformer

    • Output transformer (T2 on Charlie's - T1 on this board)
      • 200:50 Ohms = 2:1 turns ratio
      • 10 turns primary (on transistor collector), 5 turns secondary (towards output)

RF-Amp-T1.PNG

LT Spice Simulation

Transformer 35 uH

RF-AMP-LTSPICE 35uH.PNG

Charlie Morris Schematics

IF AMP

  • From Charlie's notes
    • DC Operating Point = 10 mA
    • V(emitter resistor) = 1/10 Vcc = 1.2V
      • R(emitter resistor) = 1.2V/0.01A = 120 ohms
  • Beta DC = geometric mean min/max beta at operating current
    • = sqrt(100*300) = 173
  • Beta AC = gain bandwidth product divided by operating frequency
    • Assume operating frequency of 10 MHz (my IF is actually at 9 MHz)
    • = 300/10 = 30
  • VCE = 0.7V
  • V(emitter) = 1.2V
  • V(base) = V(emitter) + VCE = 1.9V
  • Assume current in biasing resistors = 10x current needed by DC beta
    • 10 mA in C-E, beta DC less = 10 mA/173 \











0

IF Amp 0046A.jpg

IF Amp 0046B.jpg

IF Amp 0046C.jpg

IF Amp 0047A.jpg

IF Amp 0047B.jpg

IF Amp 0047C.jpg

Video

Assembly Sheet