Kits and Parts Mixers

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Kits and Parts Mixers Features in Common

  • All Ports are 50Ω
  • +7dBm Local Oscillator Injection Design
  • Full Diplexer at the IF Port
  • Optional Attenuators for RF & LO Ports
  • Available as bare PCB or kit of parts

My Typical Applications

Kits and Parts ADE-1 Mixer

ADE-1.SCH.png

ADE-1.PCB.png

Toroid Winding Direction

  • Toroids needs to be wound to match the pad locations/offsets on the PCB

Toroid-cw.jpg

ADE-1 Schematic

ADE-1 Schematic.PNG

Performance

Chart dBm-to-Volts.PNG

ADE-1 Performance.PNG

ADE-1 ElectricalSpecs.PNG

Port VWSR

  • Measured VSWR of 2.23 at 9 MHz with NanoVNA matches spec nicely

ADE-1 LO VSWR.PNG

ADE-1 IF VSWR.PNG

ADE-1 RF VSWR.PNG

ADE-1 Measurements

NanoVNA Measurements

  • No RF in
  • LO driven by NanoVNA Tx
    • About -10dBm output
  • IF output to NanoVNA Rx
  • IF at 9 MHz
    • VSWR: 2.233
    • S21 Gain: -67 dB

ADE-1.NanoVNA LO-to-IF.png

  • NanoVNA
  • No LO in
  • RF driven by NanoVNA Tx
  • IF output to NanoVNA Rx
  • IF at 9 MHz
    • VSWR: 2.216
    • S21 Gain: -42 dB

ADE-1.NanoVNA RF-to-IF.png

  • Scanning from 1 to 100 MHz

ADE-1.NanoVNA RF-to-IF 1-100MHz.png

tinySA Measurements

LO to IF port isolation
  • Driven by VFO-001 3.3V squarewave output
    • Signal level about 0.5 dBm
    • CLK0 = 9 MHz into LO port
  • Monitor IF output from mixer on tinySA
    • Output through 20 dB attenuator (tinySA set to -20dB gain)

ADE-1.tinySA RF-to-IF 9Mhz-center.png

Mixer Operation
  • Driven by VFO-001 3.3V squarewave outputs
    • Signal level about 0.5 dBm
    • CLK0 = RF @7 MHz VFO-001 output with 30 dB attenuator
    • CLK1 = LO @16 MHz no attenuator
  • Monitor IF output from mixer on tinySA
    • IF out to tinySA with 20 dB attenuator (tinySA set to -20dB gain)

ADE-1.tinySA LO-16MHz RF-7MHz-to-IF 9Mhz-center.png

Bridged Tee Diplexer

Diplexor is a bandpass/band-stop filter popularized by Joe Reisert W1JR that is used after a double Balanced Mixer to provide a 50 ohm termination to all frequencies at the mixer's IF port, and to the following amplifier stage. Maintaining a consistent load at the mixer avoids overload and Inter-Modulation Distortion (IMD) effects that these mixers are prone to when not properly terminated.

LTSpice simulation

  • 9 MHz
  • FT37-67, 20T-12" = 8 uH
  • T37-17, 13T-10" = 250 nH
  • C2 adjusts peak from left to right

DIPLEXER SPICE SIM.PNG

Diplexer.PNG

Diplexer pass.PNG

Adjust Diplexer C1 (ADE-1)

  • Drive RF port from NanoVNA
  • Listen on IF port of NanoVNA
  • No drive on LO
  • 9 MHz is IF design frequency
  • Nano VNA set to scan from 1 Mhz to 30 MHz
    • Shows peak at 9 MHz

ADE-1.NanoVNA RF-to-IF.png

  • Scan from 8 to 10 MHz
  • Adjust C1 to peak near 9 MHz
    • Eliminate double peaks

ADE-1.NanoVNA RF-to-IF 8-10MHz.png

Kits and Parts Diode Mixer

DBDM.SCH.png

DBDM.PCB.png

Videos