A Termination Insensitive Amplifier for Bidirectional Transceivers
Contents
W7ZOI Design
- Paper - A Termination Insensitive Amplifier for Bidirectional Transceivers - W7ZOI (Wes Hayward) design
- Transistor Models and the Feedback Amplifier
- Termination Insensitive - input impedance that does not depend upon the output load
- Bi-directional - amplifiers in both directions
- 50 ohms in/out
- BNC or SMA Connectors
- Transformer-less
- Power applied to one half at a time - determines signal flow direction
- Use
- Between RF/LO mixer (IF output/input) and crystal filter
- Between Crystal Filter and Product Detector / Balanced Modulator
Schematic in KiCAD
- Single channel
- With SPICE directives
- Both channels
- With SPICE directives
NGSPICE Simulation
- NGSPICE run from KiCAD
- +24 dB @12V
- 2N3904 Alternate Node Sequence (MMBT3903 - SOT23)
- KiCAD order 1 2 3 is the SPICE normal order
- NGSPICE order: 3 1 2
- Closely matches
- Across Band
CAD
SMT Build
Videos
