SDR transceiver

General info

• SDR wiki
• Quadrature Mixers, IQ Demodulation, and the Tayloe Detector
• A Software-Defined Radio for the Masses, Part 1
• Hardware Implementation of Software Radio Receivers

Main concept

• Fully open source design include HW and SW
• Only free development SW
• Single board design to keep design simple
• SMT design
• Standalone battery powered device

Folder structure

• schematic/ - KiCad PCB design. Schematic, PCB routing, manufacture documentation.
• simulation/ - HW components spice simulations.
• firmware/ - firmware.
• calculations/ - calculations and considerations needed for HW/SW design implementation.
• datasheets/ - datasheets used during design implementations.
• tests/ - projects to check design components functionality.

Block diagram

See schematic/sdr-trx/sdr-trx.sch which is top level schematic.

Great thanks for sharing their approaches knowledges and considerations

• M0NKA http://www.m0nka.co.uk/ - Small and inexpensive homebrew HF radio.
• https://www.flexradio.com/ - RF transceivers.
• https://elecraft.com/products/kx3-all-mode-160-6-m-transceiver - SDR transceiver.
• IN3OTD https://www.qsl.net/in3otd/index.html - lot of very useful information information and approaches. RF PA got from this site.
• https://ludens.cl/Electron/Electron.html - Here's the best explanation of common mistake in push-pull RF PA transformers design I've ever seen. See https://ludens.cl/Electron/mosfetamps/amps.html.
• https://www.youtube.com/watch?v=byF1FLdbUiA - Simple and understandable explanation of a directional coupler.
• https://rf-tools.com/lc-filter/ - Perfect on-line filter calculator.