What is it?

SDR-3 is an assembly kit for learning RF communication signal processing. The kit contains 2 PCB boards, RF analog front-end unit"SDR-3A" and digital processing unit "SDR-3D". You can monitor processing status of STM32F405 by spectrum on LCD. It enables you build up SSB SDR transceiver adding RF power amplifier etc.

Designed by Ichirou Ogawa (Ojisankoubhou)

Why did you make it?

For learning RF communication signal processing.

What makes it special?

(1) In addition to the transmission / reception setting, spectrum and frequency characteristics can be checked on the color LCD.

You can monitor the following information.

・3 types of SSB signal generation method selectable

・Spectrum monitoring of signal processing in micro procecssor

・Transmit / receive loop back for self test

・Network frequency characteristic self-measurement of analog filter on SDR-3A

・Transmission / reception test signal generator

(2) ARM Cortex-M4 microcomputer (STM 32 F 405 RGT 6) with built-in FPU (Floating Point Unit) is mounted on SDR-3. It enables you to learn signal processing programming skills for radio communication.

(3) You can select the following three types of SSB signal generation method.

(1) Phase method

(2) Weaver method

(3) Fourth method (ogawa method)

(4) This kit enables you to measure carrier wave frequency very precisely refer to AM radio wave,its resolution is more precise than FFT (Fast Fourier Transform) method. It is easy to measure the carrier frequency, and it is also possible to caliblate the frequency deviation error of oscillator.

(5) This kit removes proximity spurs (carrier leaks and image signals) generated by analog mixers using 3-stage crystal filter.

Please check Documentation Link to get hex file(STM32F405) and manuals for assembling and operation