Low cost Software Defined Radio (SDR) Panorama

bladeRF - low-cost, professional USB 3.0 Software Defined Radio

bladeRF is a Software Defined Radio (SDR) platform designed to enable a community of hobbyists, and professionals to explore and experiment with the multidisciplinary facets of RF communication. By providing source code, thorough documentation, easy to grasp tutorials, and a place for open discussion modern radio systems will be demystified by covering everything from the RF, analog, and digital hardware design to the firmware running on the ARM MCU and FPGA to Linux kernel device drivers.

Lime Microsystems - configurable 3G & 4G transceivers

Here is an interesting low cost SDR "thing" (Thank you Akash !)

ASRP3 is based on a classical I/Q direct conversion architecture using ADL5380 I/Q demod chip from Analog Device, as well as their famous AD9262 10 MHz 16 bits sigma delta ADC.

The AD9262 presents 87 dB dynamic over the 10 MHz range, due to the 16 bits...Which is good for the price !

Indeed, final dynamic will not be 87 dBs due to input stages, but we should obtain pretty good results from this device anyway...And you can still implement clever decimation to increase dynamic on a reduced bandwidth.

This being said, this receiver will tune its 10 MHz SDR window from 400 to 4400 MHz, which opens a bunch of possibilities.

Here we are, the new version is coming, and maybe already available. Same principle than original FunCube Dongle (A "TV tuner like" radio in front of a low cost 16 bit soundcard -> USB chipset).

But this time, sampling rate is 192 KSamp/s, and thus SDR coverage is close to 2 x 96 KHz which means 192 KHz.

And probably more important for potential users : RF coverage starts from 150 KHz to 240 MHz as well as 420 to 1900 MHz, bringing Shortwave capability in top of most used V-UHF spectrum capability.

The SDR-ONE is a low cost, high performance transmit / receive module for experimentation and integration into products. The module can be used stand alone or plugged into other products. It offers very high performance with the use of a 14 bit ADC/DACs. The SDR-ONE RX/TX module offers 48,96 and 192 KHz receive bandwidths over I2S, optical audio (S/PDIF) and IQ analog out. In addition, up to 40 KHz of BW can be transmitted at a 48 Khz sample rate. The SDR-ONE sets the RX sample rate of the sound-card when using the S/PDIF or I2S outputs. In TX, I/Q signal is received via the IQ analog input or the I2S master port. The FPGA and flash memory can be reprogrammed over the built in USB port in seconds without the need of a special programming cable. The FPGA UCF file and code examples are supplied for those willing to write their own code.

PERSEUS SDR software version 4.00b is released.

QS1R from Software Radio Laboratory LLC, is a direct sampling SDR receiver covering 10 KHz to 62.5 MHz. It is based on LTC2208 16 bits 130 MS/s A2D associated to a Cyclone III FPGA.

Connected to a PC through its USB 2.0 interface, it can be operated with its software companion "SDRMAX"   http://www.srl-llc.com/qs1r_latest/index.html   or with HDSDR or Winrad (see previous articles for those softwares).

It has to be noticed that SDRMAX source code is available...

SDR# (read SDR Sharp) is a high performance Software Defined Radio application. It is written in C# with both object design correctness and performance in mind. The project started as a simple proof of concept program to get hands into DSP techniques and has evolved to what it is today: A fully featured SDR capable of handling samplerates from kHz level soundcards up to multi hundred MHz dedicated samplers, thanks to its multi-core architecture.

Myriad – RF   Created by Azio - order a board ($299) - download KiCAD file The Myriad – RF board is a multi-band, multi-standard RF module, based on the state of the art LMS6002D transceiver IC by ...

EasySDR is an other "FunCube Dongle like" device. Characteristics and performances are very similar...If not the same.

It is compatible with most well known SDR software.

Specification:
- 64 MHz - 1700 MHz frequency range,
- 48 kb/s audio bandwidth,
- DLL interface for HDSDR application,
- small device size: 37x22x78 mm

This can be considered as a new version of AFEDRI SDR, allowing to send I/Q samples on IP network in addition to local USB.

Performances are the following :

-0.1 to 30 MHz (default)

-0.1 to 70 MHz with performance compromises

-80 MHz oversampling rate @ 12 bits

-Received BW up to 1225 MHz on ethernet

-Received BW up to 230 KHz on USB

For the rest : same functionalities than AFEDRI SDR.

Block diagram here : http://4z5lv.net/index.php/afedri-sdr-net-description?showall=&start=1

Full schematics here : http://4z5lv.net/index.php/downloads/category/2-documentation?download=56:afedri-sdr-net-schematic

With a simple digital TV USB capture card, you can build your own software defined radio or spectrum analyzer. While it may not be as cool as [Jeri Ellsworth]'s SDR, it's still very useful and only requires $20 in hardware.

However, be carefull, you have what you get for 20 $...I/Q interface is 8 bits which means around 48 dB maximum dynamics. This is OK for a single signal, isolated from others by physical filtering (TV signal indeed !), but not enough for narrowband multisignal handling (14 to 16 bits being a minimum).

A solution is to oversample your baseband, and then decimate to increase the effective number of bits. For example, if you oversample by 128 around 4 Msamp/s, you will obtain an effective sampling rate of around 31 Ksamp/s, thus a combined I/Q bandwidth of 31 KHz after digital filtering, with an effective number of bits of 8+3,5=11,5 bits (70 dB dynamic).

Analyze of the used Realtek chipset shows analog I/Q signal if fed to digital A/D-USB chip via 4 capacitors (I/Q differential interface). It is then possible, through HW modifications, to interpose 2 differental analog baseband filters in order to improve the system in addition to oversampling...

In conclusion, an interesting solution, close to the "funcube dongle" concept, already presented here. But the funcube has more dynamic, by design.

A fast, free C FFT library; includes real-complex, multidimensional, and parallel transforms. Benchmarked against many other FFTs.