AFEDRI SDR Hardware Description

AFEDRI SDR it is direct sampling Software Defined Receiver (see picture below)

AFEDRI SDR has next parameters:

RX frequencies:

0.1MHz-30MHz (Low Pass filter assembled (LPF) - default assembly configuration)

Special , non standard SDR revision can be assembled to provide aliased reception mode 40MHz - 80MHz or 80MHz-120MHz (In aliased mode, LPF is not assembled, external Band Pass Filter (BPF) have to be used instead)

Noise Figure: ~17dB (for 1MHz-30Mhz range)*

*input VGA (Variable Gain Amplifier) is tuned to have variable Gain from -6dB up to +44dB

Output data format: two 16-bit I/Q channels (audio stereo stream emulation)

Maximum Receiving bandwidth:

BW = up to 240kHz (for 250 ksamples/s sample rate) - 192k version (current design revision)

BW = 90kHz (96ksamples/s) - 96k version (old design revision)

 

 

RF ADC sampling rate: 76.800MHz (or alternatively 79.872MHz)

 

Power Supply Voltage: 5V (supplied from USB bus)

Power Supply current: 330mA

Latest news is: In new HW revision it is possible to combine two AFEDRI SDR (one fully assembled and second containing only RF Front-End) to build Dual Channel (Diversity) Receiver, that can be used together with Linrad and MAP65 applications!


 


AFEDRI SDR in box

 

The Newest High-Speed AFEDRI SDR-USB-HS  revision

The SDR is designed to be connected to Personal Computer (PC) by Full Speed USB link and supplies to PC two quadrature channels I/Q with sample rate up to ~250k samples per second 16-bit each channel for latest revision on SDR design. Published on this site schematic can use STM32F105xxx processor to get maximum RX bandwidth, it needs little schematic changes, plus new firmware.

You can download recorded in Winrad audio files:

- I/Q wave files recorded with different applications

- I/Q with 192ksamples/s sample rate

- I/Q with 250ksamples/s sample rate 14Mhz band (contest)

- I/Q with 250ksamples/s sample rate 7Mhz band (contest)

 

From PC side of view, the SDR is presenting USB Compisite Device, that contains two USB functions:

The SDR doesn't need any additional driver installation on most of Operational Systems (OS) used on PC today it was successfully tested under next OS Windows XP SP2, Windows Vista 32 bit, Windows 7 32 bit, Linux Fedora 12.

The SDR compatible and working with most PC SDR software that working with PC Spund Card device, like Wirad (and its different clones), Linrad, SDR Console, Rocky etc...

Additional  SDR Control software is need to control over the AFEDRI SDR frequency, RF gain/attenuation and additional parameters.  SDR Control software can be used stand alone with any SDR software, or as plug-in for Winrad and/or Linrad (only Windows version yet) software, so SDR's frequency can be displayed and changed directly from Winrad GUI (please check my Download page).


The SDR Control software was written using Qt Cross-platform application framework from Nokia, so both Windows and Linux software versions can be compiled and have similar Graphical User Interface (GUI) under both OS-es.