AFE822x SDR-Net (Dual Channel)

AFE822x SDR-Net ( Dual Channel ) Features

● Synchronized (diversity) or separated (independent) Dual Channel reception mode
● 100 kHz to 30.00MHz continuous frequency range
● 2-x Direct sampling receivers
● Digital down-conversion
● Dual 12- bit 76.8 MSPS A/D conversion
● Up to 900kHz recording and processing bandwidth for each channel in dual channel mode or 1.8MHz in single channel mode
● Waterfall display functions, when used with appropriate software
● Recording and playback, when used with appropriate software
● Sensitivity -  MDS -136 dBm at 500Hz bandwidth
● USB 2.0  interface (Full Speed)
● LAN (network) interface for remote access
● Compatible with: Linrad, Winrad, HDSDR, SDR Console
SDR-radio, CuteSDR, Studio1, SdrDX, Quisk, PowerSDR_mrx
● Powered from USB or   7-10VDC from External Power Supply
● Dimensions 120mm deep x 78mm wide x 27mm height
● Price - 309$ (no box) 359$ (boxed)

AFE822x SDR-Net  is a Dual Channel direct sampling Software Defined Receiver (see picture below)  it has ability to send it's received I/Q stream trough two different interfaces:

- Network (LAN)


AFE822x SDR-Net  Dual Channel receiver has the following specification:

Frequency Coverage:

0.05MHz-35MHz: 35MHz Low Pass Filter (LPF) assembled  - standard  configuration

Per user request the special SDR revision can be assembled that is able to work  in aliased mode (36Mhz-72Mhz or 72Mhz-108Mhz) , in this revision the 30MHz LPF is not assembled and external Band Pass Filters (BPF) have to be added by user.

Noise Figure: ~11dB (in 1MHz-30Mhz range and maximum gain 35dB)*

*input VGA (Variable Gain Amplifier) has variable Gain from -10dB up to +35dB

MDS: -136 dBm at 500Hz bandwidth

Output data format:

 1. four16-bit I/Q channels (in dual channel mode)

 2. two 16-bit I/Q channels (in single channel mode)

Maximum Receiving Bandwidth:

BW = up to 900kHz for each channel (for 1000 ksamples/s sample rate) -  using Network connection in Dual Channel mode

BW = up to 1800kHz (for 2000k samples/s sample rate) -  using Network connection in single Channel mode

BW = up to 110kHz (for 125k samples/s sample rate) -  using USB connection and Dual Channel Mode

BW = up to 230kHz (for 250k samples/s sample rate) -  using USB connection and Single Channel mode


*Notes: The real sample rate value can be little bit different from the numbers printed above and depends mostly on Main Clock value

 RF ADC sampling rate: 76.800MHz

 Power Supply Voltage Requirements:

5V (supplied from the PC's USB bus or from external) or  from external power supply able to provide 5VDC +/-0.2V).

 7-10V DC to the DC power connector.

Power Supply Current Requirements:

~ 580mA from USB or  external 7.5V power supply. Mini-USB Y-cable is used to get power from USB line, so two free USB connectors required to get power for AFEDRI SDR-Net-x2 from USB line.


AFE822x SDR-Net  Dual Channel rev0.1 in Box  (SMA and BNC connector's assembly)


AFE822x SDR-Net (Dual Channel) rev.0.1 in 1455J1201 box (SMA and BNC connectors assembly)


AFE822x SDR-Net  Dual Channel rev.0.1 in Box back panel

The AFE822x SDR-Net is designed to be connected to Personal Computer (PC) by two alternative interfaces:

1. Ethernet Network connection.

This can now provide up to 2000kHz sample rate (in single channel mode two quadrature channels, 2 x I/Q 16-bit sample size) and up to 1000kHz for each reception channel (in Dual Channel mode, 4 x I/Q 16-bit sample size)

 2. Full Speed USB

This interface is identical to the one in earlier AFEDRI SDR versions. It sends  to PC two quadrature channels I/Q with sample rate up to 250k samples per second 16-bit sample size - equivalent to two audio channel ( in single channel mode) or 125k samples per second - equivalent to four audio channels (in Dual Channel mode).

For more information about USB functionality of the device please read AFEDRI SDR description.


Dual Channel Reception Mode (two HDSDR instances for two different bands)

When the AFE822x SDR-Net is connected to a PC using network interface, it is compatible with the following PC SDR software:

In addition to this there is software plugin - SDR Network Control Box plugin , that can be used with Winrad, HDSDR, Studio1  this allows control of the AFE822x SDR-Net parameters (frequency, RF gain/attenuation etc...) and reception of the UDP I/Q data stream.

The SDR Network Control Box software can be used as stand alone application for SDR configuration and/or as plug-in for Winrad/HDSDR/Studio1 software (under Windows). 

When working together with Linrad or SDR-Radio.v2 software - no additional software or plug-ins are required.

AFEDRI SDR-Net can be used together with MAP65-IQ software when working with Linrad or SDR-Radio software.

SDR Network Control Box screen-shot.

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 operating systems .




AFE8220 SDR-Net  is based on the new  integrated circuit AFE8220 and uses same PCB size as  single channel AFEDRI SDR-Net of previous revisions.

The difference between AFE822x SDR-Net and  AFEDRI SDR-Net x2 Dual Channel versions is next:

1. Single Dual Channel AFE8220 Front-End is used in new design. 

The Structure Diagram of AFE822x SDR-Net  can be found on the picture below:


There is short structure diagram description:

LPF - Low Pass Filter, in default configuration is using as anti-aliasing filter for from DC to ~28MHz (or any frequency located below Nyquist limit).

VGA - Variable Gain Amplifier, it is built using AD8369 IC from Analog Devices, and adjusted in in this design to give amplification/attenuation of input signal from -10dB up to 35dB.

Direct Sampling Receiver Front End - i.e Analog Front End is built on AFE8220 integrated circuit, it is heart of SDR, that providing Input RF signal ADC sampling, mixing and digital filtering, base-band signal data is outputs through specific serial interface, that very similar to I2S but not 100% compatible, for example used in my design CPU, need external help from CPLD, to accept data incoming data. More information about you can find in datasheet. Please pay attention that this device is not recommended  by Texas Instruments for new design, but there is many way to achieve this integrated cuicuits from different sources. And I am sure HAM radio society can use it in their applications.   

CPLD - main function of this device to convert AFE8220 integrated circuit base-band (output data) serial protocol to  communication protocol that is supported by microprocessor.

CPU - it ARM Cortex-M3 architecture microprocessor - STM32F207VC , from ST Microelectronics, it controls Analog Frond End by additional SPI control channel, receive processed base-band data from Front End and transfer it to PC using Network interface or USB link and software USB Audio Device and HID device emulation.

Ethernet (RMII PHY) - Ethernet physical layer transceiver, working as interface between LAN (network) and CPU

Power Supply - Whole receiver is supplied from 5V voltage of USB line, and there is three voltages +1.8V -digital, 3.3- digital and 3.3V analog, that generated from single supply voltage.

External Power Supply - Is used as alternative power supply from external DC source, like battery or transceiver power supply, it is  switched DC/DC power supply the SDR. Can work from external sources that gives DC voltage in range 7VDC-10VDC

Power Switch - automatically switches between USB or external voltage source.


The mechanical size of the AFE822x SDR-Net PCB  was designed for installing two stacked PCB into aluminum  box  manufactured by Hammond the manufacturer part number of boxes is:



There is lot of files on my download page, software sources and  firmware for your attention.

You can visit also Yahoo AFEDRI SDR user group

Any question? Please ask me by email. alex(*) or alex(*)

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Please check it periodically for latest version.

Further information will be later.