Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system.
Experimenting with software defined radio used to be expensive, but now it is cheap. Nowadays it is very cheap to start experimenting with SDR. Most receivers use a variable-frequency oscillator, mixer, and filter to tune the desired signal to a common intermediate frequency or baseband, where it is then sampled by the analog-to-digital converter. Cheapest wide receiving range well working device is to use suitable DVB-T receiver stick (10-20 Euros/Dollars) and suitable software (very many alternatives, for example SDRsharp and Gnu Radio).
My article Software defined radio with USB DVB-T stick started the long list of SDR related postings. The newest postings now are Filter measurements with RF noise source and Antenna measurements with RF noise source.
432 Comments
Tomi Engdahl says:
(Ab)use an Arduino as AM Music Transmitter! © CC BY
See how an Arduino can be transmit music over AM with only a few lines of code.
https://create.arduino.cc/projecthub/michalin70/ab-use-an-arduino-as-am-music-transmitter-d3b6e3
Tomi Engdahl says:
http://www.icrobotics.co.uk/wiki/index.php/Turning_the_Raspberry_Pi_Into_an_FM_Transmitter
Tomi Engdahl says:
EmbedINN’s iotSDR Aims to be a One-Stop IoT Development Board for All Things Radio
https://www.hackster.io/news/embedinn-s-iotsdr-aims-to-be-a-one-stop-iot-development-board-for-all-things-radio-d45b7c54c485
A Xilinx FPGA and two Microchip transceivers at its heart, the ioTSDR is certainly feature-packed — though there’s no sign of prototype yet.
Pakistani IoT specialist embedINN is turning to crowdfunding to produce a development board aimed at communications projects, powered by a Xilinx Zynq FPGA and Microchip RF transceivers: the iotSDR.
“It has two Microchip AT86RF215 frontends, capable of providing I/Q streams and modem functionality for the Xilinx ZYNQ SoC, as well as a MAX2769 GNSS chip for custom GPS, Galileo, BieDou, and Glonass development. It is also compatible with the popular GNURadio SDR software.
“If you want to design and develop a physical layer protocol for IoT – a protocol like LoRa, Sigfox, WightLess, Bluetooth, BLE, 802.15.4, ZigBee, or something of your own — this board is for you. It is also a great place to start if you want to build a custom IoT gateway along the lines of The Things Network, LPWAN, or Google Thread.”
The twin Microchip AT86RF215 transceivers support operation in a range of radio frequencies — 389.5-510 MHz, 779-1020 MHz, and 2400-2483.5 MHz – while the Maxim MAX2769B provides connectivity to global navigation satellite systems (GNSS) for position or timing
Tomi Engdahl says:
I did this almost a year ago with less than $200 of electronics to spoof gps
https://youtu.be/fAaiNOZmM20
Tomi Engdahl says:
This website details the design and construction Wave Bubble: a self-tuning, wide-bandwidth portable RF jammer. The device is lightweight and small for easy camouflaging: it is the size of a pack of cigarettes.
https://www.ladyada.net/make/wavebubble/
Tomi Engdahl says:
Build a Long-Distance Data Network Using Ham Radio
https://spectrum.ieee.org/geek-life/hands-on/build-a-longdistance-data-network-using-ham-radio
In 2013, I was looking at a protocol called NBP, used to create a data network over amateur radio links. NBP was developed in the 2000s as a potential replacement for the venerable AX.25 protocol [PDF] that’s been in use for digital links since the mid-1980s. I believed it was possible to create an even better protocol with a modern design that would be easier to use and inexpensive to physically implement.
It took six years, but the result is New Packet Radio (NPR), which I chose to publish under my call sign, F4HDK, as a nom de plume. It supports today’s de facto universal standard of communication—the Internet’s IPv4—and allows data to be transmitted at up to 500 kilobits per second on the popular 70-centimeter UHF ham radio band.
70-cm band permits long-distance links even when obstructions prevent line-of-sight transmissions.
I turned to ISM (industrial, scientific, and medical) chips. These are transceivers designed to operate in narrow radio frequency bands that were originally allocated for noncommunication purposes, such as RF heating. However, the ISM band has become popular for communications as well because typically a license is not required for its use. In Africa, Europe, and North Asia, there is an ISM band lying inside the 70-cm ham radio band at 434 megahertz, so commercial ISM chips are available for this frequency.
around the Si4463 [PDF] ISM transceiver: It’s cheap, flexible, and available in many modules and breakout boards
widely available external 20-watt amplifiers for handheld radios designed for the European-developed Digital Mobile Radio (DMR) standard,
The ISM transceiver is connected to an Mbed Nucleo STM32 L432KC microcontroller, which uses an Arm Cortex CPU.
This microcontroller is in turn connected to an Ethernet interface, and it takes care of all the details of running the NPR protocol. Any connected PC or network sees the radio link as just another IPv4 connection with no need to install specific NPR software. The NPR modem can be configured over this link or via a USB connection. The total cost of the hardware is about US $80
The NPR protocol is based on a hub-and-spoke model, in which a central modem links several client modems. Currently there can be as many as seven modems, although I plan to expand this to 15. The theoretical maximum distance between a client modem and the central modem is 300 kilometers. This limit arises because NPR uses a managed time-division multiple access (TDMA) technique
NPR New Packet Radio
IP over 430MHz Ham Radio, up to 500kbps, 20W RF.
Extension for HSMM-Hamnet-AREDN. 100% open-source.
https://hackaday.io/project/164092-npr-new-packet-radio
Tomi Engdahl says:
Tracking down a water leak with rtlamr
https://irrational.net/2019/03/26/tracking-down-a-water-leak/
An rtl-sdr receiver for Itron ERT compatible smart meters operating in the 900MHz ISM band.
https://github.com/bemasher/rtlamr
Tomi Engdahl says:
AN INTRODUCTION TO PAGERS WITH THE HACKRF PORTAPACK AND AN RTL-SDR
https://www.rtl-sdr.com/an-introduction-to-pagers-with-the-hackrf-portapack-and-an-rtl-sdr/
Tomi Engdahl says:
Universal Radio Hacker: Investigate Wireless Protocols like a Boss
https://hakin9.org/universal-radio-hacker-investigate-wireless-protocols-like-a-boss/
Tomi Engdahl says:
Combine a Raspberry Pi and an inexpensive SDR dongle to create a remote spectrum monitoring device.
Run OpenWebRX on balena to Monitor Local Radio Signals
https://www.hackster.io/alan-boris/run-openwebrx-on-balena-to-monitor-local-radio-signals-21f78a
Combine a Raspberry Pi and an inexpensive SDR (Software-Defined Radio) dongle to create a remote spectrum monitoring
Tomi Engdahl says:
https://walabot.com/diy
Tomi Engdahl says:
Build a Mini SDR Radio Using an FV-1 Audio Processor and an Si5351 Clock Generator
The Mini SDR Radio features an LTC6252 low-noise op-amp for RF input and gain, an OLED display, and an aluminum enclosure.
https://www.hackster.io/news/build-a-mini-sdr-radio-using-an-fv-1-audio-processor-and-an-si5351-clock-generator-872ab8cc3092
Tomi Engdahl says:
Compact Si5351 based SDR
https://circuitsalad.com/2020/01/06/compact-si5351-based-sdr/
Tomi Engdahl says:
RF Modulation: Crash Course For Hackers
https://hackaday.com/2020/01/28/rf-modulation-crash-course-for-hackers/
Tomi Engdahl says:
https://hackaday.com/2020/01/28/eric-talks-crystal-radios/
Tomi Engdahl says:
The RFI Hunter: Looking For Noise In All The Wrong Places
https://hackaday.com/2020/01/15/the-rfi-hunter-looking-for-noise-in-all-the-wrong-places/
Next time you get a new device and excitedly unwrap its little poly-wrapped power supply, remember this: for every switch-mode power supply you plug in, an amateur radio operator sheds a tear. A noisy, broadband, harmonic-laden tear.
The degree to which this fact disturbs you very much depends upon which side of the mic you’re on, but radio-frequency interference, or RFI, is something we should all at least be aware of. [Josh (KI6NAZ)] is keenly aware of RFI in his ham shack, but rather than curse the ever-rising noise floor he’s come up with some helpful tips for hunting down and eliminating it – or at least reducing its impact.
https://www.youtube.com/watch?v=QQzmMOJvFfc
Tomi Engdahl says:
SP6T Wideband RF Switch (5 – 3000 MHz)
https://hackaday.io/project/169591-sp6t-wideband-rf-switch-5-3000-mhz
Single pole 6 throw RF switch ; 3 bit control channel ; 3-5V operation ; Decent isolation ; low insertion loss ; Tinker board add-on.
Tomi Engdahl says:
https://hackaday.com/2019/11/12/hf-propagation-and-earthquakes/
Tomi Engdahl says:
Just How Simple Can A Transceiver Be?
https://hackaday.com/2019/11/09/just-how-simple-can-a-transceiver-be/
We’ve frequently talked about amateur radio on these pages, both in terms of the breadth of the hobby and the surprisingly low barrier to entry. It’s certainly the case that amateur radio does not have to mean endlessly calling CQ on SSB with an eye-wateringly expensive rig, and [Bill Meara N2CQR] is on hand with a description of a transceiver that’s so simple it only uses one transistor.
https://soldersmoke.blogspot.com/2019/10/more-on-et-2-better-pictures-and-more.html
Tomi Engdahl says:
DSP Spreadsheet: IQ Diagrams
https://hackaday.com/2019/11/15/dsp-spreadsheet-iq-diagrams/
Tomi Engdahl says:
A Radio For The Apocalypse
https://hackaday.com/2019/11/15/a-radio-for-the-apocalypse/
Tomi Engdahl says:
All Your SDR Software In A Handy Raspberry Pi Image
https://hackaday.com/2019/12/20/all-your-sdr-software-in-a-handy-raspberry-pi-image/
Tomi Engdahl says:
LuaRadio Gives Insight Into SDR
https://hackaday.com/2019/12/24/luaradio-gives-insight-into-sdr/
In theory, you shouldn’t need any help to develop a software-defined radio (SDR) application. But in real life you really don’t want to roll your own code every time to read the IQ samples, perform various transformations on them, and then drive audio output. At worst, you’ll use some libraries (perhaps GNU Radio) but usually, you’ll use some higher-level construct such as GNU Radio Companion (GRC). GRC is a bit heavyweight, though, so if you’ve found it daunting before, you might check out some of the material on the LuaRadio website.
https://luaradio.io/new-to-sdr.html
Tomi Engdahl says:
A Mini SDR Receiver Using An Audio DSP
https://hackaday.com/2020/02/01/a-mini-sdr-receiver-using-an-audio-dsp/
Software defined radio or SDR is the most exciting frontier in the field of radio, transferring as it does all signal functions from the analogue to the digital domain. Radios using SDR techniques can be surprisingly straightforward and easy to understand, and [Ray Ring]’s little SDR receiver manages to combine this with the novel use of an audio DSP rather than a computer to perform its SDR functions.
The front end is a conventional enough direct conversion design with an Si5531 clock generator providing I and Q phase-shifted local oscillator signals to a TS3A5017 analogue switch used as a mixer. An unexpected presence is an LTC6252 op-amp as an RF amplifier, but the special part comes after the I and Q baseband signals have been filtered. The SDR part of this receiver is an audio DSP, but it’s one that might not be an immediate choice. The Spin Semiconductor FV-1 is a dedicated digital reverb chip for musical effects boxes, but it comes with the feature that its internal DSP core can access custom code from an external ROM.
Compact Si5351 based SDR
https://circuitsalad.com/2020/01/06/compact-si5351-based-sdr/
Tomi Engdahl says:
The $50 Ham: Going Mobile
https://hackaday.com/2020/02/05/the-50-ham-going-mobile/
Tomi Engdahl says:
A 60 GHz Phased Array
https://hackaday.com/2020/01/31/a-60-ghz-phased-array/
Tomi Engdahl says:
Spectrum analyzer from a CC1350 launchpad
Putting a junk radio development kit to some use
https://hackaday.io/project/169451-spectrum-analyzer-from-a-cc1350-launchpad
Tomi Engdahl says:
This Element14 Community member is designing a world band radio receiver board with the help of a MKR ZERO.
https://www.element14.com/community/community/project14/rf/blog/2019/12/19/planetcatcher-building-a-world-band-radio-receiver
Tomi Engdahl says:
(Ab)use an Arduino as AM Music Transmitter! © CC BY-SA
See how an Arduino can be transmit music over AM with only a few lines of code.
https://create.arduino.cc/projecthub/michalin70/ab-use-an-arduino-as-am-music-transmitter-d3b6e3
Tomi Engdahl says:
https://www.rtl-sdr.com/rtl-sdr-tutorial-pocsag-pager-decoding/
Tomi Engdahl says:
DIY SW, MW, SDR Radio with ESP32 and Si5351
Sensitive retro look radio capable of receiving signals from middle wave and short wave band.
https://www.hackster.io/mircemk/diy-sw-mw-sdr-radio-with-esp32-and-si5351-b580de
This radio receiver is capable of receiving all MW and SW bandwidth, and can also operate as an SDR receiver, so with the help of PC and appropriate software we can decode many different types of signals.
The mixer is a well known NE612 (or NE602, SA602, SA612).
ESP32 microcontroller, Si5351A I2C Signal Generator module board and 1.8 inch 128×160 TFT LCD with ST7735 chip. A rotary encoder is used to change the frequency. You can download the code below or directly from autr page : https://tj-lab.org/2019/02/17/vfo5/
Tomi Engdahl says:
Stout Homebrew Radio Pumps Out 200W Of AM Goodness
https://hackaday.com/2020/02/20/stout-homebrew-radio-pumps-out-200w-of-am-goodness/
Tomi Engdahl says:
RF Shield Turns Arduino (And PC) Into Shortwave Radio
https://hackaday.com/2020/02/14/rf-shield-turns-arduino-and-pc-into-shortwave-radio/
. If you want an introduction to SDR, Elektor now has an inexpensive RF shield for the Arduino. The Si5351-based board uses that oscillator IC to shift RF signals down to audio frequencies and then makes it available to the PC to do more processing.
Elektor SDR Hands-on Kit
https://www.elektor.com/elektor-sdr-hands-on-kit
Tomi Engdahl says:
An RF Engineer’s FPGA Learning Journey
https://hackaday.com/2020/03/12/an-rf-engineers-fpga-learning-journey/
[KF5N] admits he’s not a digital design engineer; he’s more into the analog RF side of things. But he’s recently taken on a project to communicate between a Ubuntu box and an Intel MAX10 FPGA. He did a presentation at a recent ham radio convention about what he’d learned and how you could get started.
An FPGA Learning Experience | 2019 TAPR DCC
https://www.youtube.com/watch?v=HaD_ExYgMeM
Tomi Engdahl says:
The ESA Reviews Software Defined Radios
https://hackaday.com/2020/04/08/the-esa-reviews-software-defined-radios/
If you want to go to the next level with software defined radio (SDR), there are a lot of choices. The RTL-SDR dongles are fine, but if you get serious you’ll probably want something else. How do you choose? Well, your friends at the European Space Agency have published a paper comparing many common options. True, they are mostly looking at how the receivers work with CubeSats, but it is still a good comparison.
The devices they examine are:
RTS-SDR v3
Airspy Mini
SDRPlay RSPduo
LimeSDR Mini
BladeRF 2.0 Micro
Ettus USRP B210
Pluto SDR
They looked at several bands of interest, but not the HF bands — not surprising considering that some of the devices can’t even operate on HF. They did examine VHF, UHF, L band, S band, and C band performance. Some of the SDRs have transmit capabilities, and for those devices, they tested the transmit function as well as receive.
The review isn’t just subjective. They calculate noise figures and dynamic range, along with other technical parameters.
https://gitlab.com/librespacefoundation/sdrmakerspace/sdreval/-/raw/master/Report/pdf/Evaluation_of_SDR_Boards-1.0.pdf
Tomi Engdahl says:
Historic first Trans-Atlantic contact made on 432 MHz – Tues 7th April 2020
https://ei7gl.blogspot.com/2020/04/first-trans-atlantic-contact-made-on.html
https://qrznow.com/historic-first-trans-atlantic-contact-made-on-432-mhz-tues-7th-april-2020/
Tomi Engdahl says:
https://pentestmag.com/broadcast-signal-intrusion-with-rpi-zero-and-an-old-rusty-guitar-string/
Tomi Engdahl says:
SOFTWARE-DEFINED RADIO MADE EASY
https://hackaday.com/2020/04/11/software-defined-radio-made-easy/
Tomi Engdahl says:
DRAGONOS: DEBIAN LINUX WITH PREINSTALLED OPEN SOURCE SDR SOFTWARE
https://www.rtl-sdr.com/dragonos-debian-linux-with-preinstalled-open-source-sdr-software/
Tomi Engdahl says:
https://ei7gl.blogspot.com/2020/04/first-trans-atlantic-contact-made-on.html
Tomi Engdahl says:
The StixRF is an SDR receiver in USB stick form with a tunable range of 70 MHz to 6 GHz and 40 MHz bandwidth.
The Bigger Stick in RF: StixRF Wideband SDR Receiver
https://www.hackster.io/news/the-bigger-stick-in-rf-stixrf-wideband-sdr-receiver-04caca80089b
StixRF is an SDR receiver in USB stick form with a tunable range of 70 MHz to 6 GHz and 40 MHz bandwidth.
Tomi Engdahl says:
Scott Tilley’s quarantine project was a little unusual: Building an antenna to find LES-5, an experimental military communications satellite launched in 1967. He believes it may be the oldest satellite that’s still broadcasting.
Long-Lost U.S. Military Satellite Found By Amateur Radio Operator
https://www.npr.org/2020/04/24/843493304/long-lost-u-s-military-satellite-found-by-amateur-radio-operator?utm_source=facebook.com&utm_term=nprnews&utm_campaign=npr&utm_medium=social
Tomi Engdahl says:
GPU Turned Into Radio Transmitter To Defeat Air-Gapped PC
https://hackaday.com/2020/04/24/gpu-turned-into-radio-transmitter-to-defeat-air-gapped-pc/
Another week, another exploit against an air-gapped computer. And this time, the attack is particularly clever and pernicious: turning a GPU into a radio transmitter.
With a GPU benchmarking program running, they switched the graphics card shader clock between its two lowest power settings, which produced a strong signal on the SDR waterfall at 428 MHz. They were able to receive this signal up to 50 feet (15 meters) away, perhaps to the annoyance of nearby hams as this is plunk in the middle of the 70-cm band. This is theoretically enough to exfiltrate data, but at a painfully low bitrate. So they improved the exploit by forcing the CPU driver to vary the shader clock frequency in one megahertz steps, allowing them to implement higher throughput encoding schemes. You can hear the change in signal caused by different graphics being displayed in the video below; one doesn’t need much imagination to see how malware could leverage this to exfiltrate pretty much anything on the computer.
TEMPEST@Home – Finding Radio Frequency Side Channels
by Mikhail Davidov and Baron Oldenburg
https://duo.com/labs/research/finding-radio-sidechannels
Tomi Engdahl says:
Who Invented Radio: Guglielmo Marconi or Aleksandr Popov?
https://spectrum.ieee.org/tech-history/dawn-of-electronics/who-invented-radio-guglielmo-marconi-or-aleksandr-popov
Who invented radio? Your answer probably depends on where you’re from.
On 7 May 1945, the Bolshoi Theater in Moscow was packed with scientists and officials of the Soviet Communist Party to celebrate the first demonstration of radio 50 years prior, by Aleksandr S. Popov. It was an opportunity to honor a native son and to try to redirect the historical record away from the achievements of Guglielmo Marconi, widely recognized throughout most of the world as the inventor of radio.
On 24 March 1896, Popov gave another groundbreaking public demonstration, this time sending Morse code via wireless telegraphy.
Tomi Engdahl says:
#TBT: Even if you’re stuck at home, the radio world can still be your oyster, thanks to this software-defined radio hack.
A $40 Software-Defined Radio
Posted 25 Jun 2013 | 12:00 GMT
https://spectrum.ieee.org/geek-life/hands-on/a-40-softwaredefined-radio
Cheap Software-Defined Radio: With some cheap hardware and free software, you can listen in on digital and analog signals across a wide range of radio spectrum.
This time I was able to get my feet wet for about $40—and the software took about 2 minutes to download, install, and run.
This minor miracle was made possible by Finnish engineering student and Linux developer Antti Palosaari. Last year, he discovered an unexpected feature of the RTL2832U demodulator chip made by Taiwan’s Realtek: Intended for decoding European HDTV broadcasts in inexpensive USB dongle-type receivers, the RTL2832U chip can also output a raw digital stream describing the amplitude and phase (so-called I/Q data) of signals over a wide range of frequencies.
Digital radio enthusiasts immediately began adapting open-source tools that can translate I/Q information into audio and data streams. The result is a low-cost SDR that can pick up a huge variety of transmissions with different modulation schemes, including stereo FM from broadcasters, digital data packets from aircraft transponders, and single-sideband modulation (SSB) dispatches from amateur radio operators. Of course, the system isn’t as sensitive as purpose-built SDRs and is incapable of transmitting a signal
Different receiver dongles pair the RTL2832U with different radio tuners, so the exact range of frequencies that can be received varies.
The P250 combines the RTL2832U with an Elonics E4000 tuner, allowing it to pick up signals from about 52 megahertz to 2.2 gigahertz, with a gap from about 1.1 to 1.25 GHz.
regulatory issues. In some countries, it’s illegal to receive any frequency you don’t have a license for, apart from public broadcast frequencies. In the United States, you’re free to pick up nearly all the signals you can receive
my home office doesn’t always get great reception. So I spent another $35 and purchased a Model B Raspberry Pi microcontroller
Following instructions on the Ham Radio Science website, I was able to download and compile some support software to use the Pi with the dongle (connected via a powered USB hub) in about 30 minutes. In turn, I connected the Pi to the home network hub in my front room via an Ethernet cable. Using the Pi lets me place the receiver farther away from local radio sources (such as my hub’s Wi-Fi transmitter) and also allows multiple machines to access the receiver easily; the Pi acts as a centralized SDR server, thanks to a command-line utility called rtl_tcp.
Tomi Engdahl says:
https://www.edn.com/understand-the-damaging-effects-of-phase-dispersion/?utm_source=newsletter&utm_campaign=link&utm_medium=EDNFunFriday-20200508
Tomi Engdahl says:
Using a low-cost TV tuner dongle and a homemade aerial, Philip Le Riche demonstrates how to capture and decode a variety of signals.
Philip Le Riche Pens a Guide to “Software-Defined Radio on a Shoestring,” Using an RTL Dongle
https://www.hackster.io/news/philip-le-riche-pens-a-guide-to-software-defined-radio-on-a-shoestring-using-an-rtl-dongle-6c9e8ec89580
Using a low-cost TV tuner dongle and a homemade aerial, Le Riche demonstrates how to capture and decode a variety of signals.
Le Riche combines the device with a homebrew aerial — one created from a co-axial lead taken from an old television, and another made using a co-ax connector and a single piece of stiff wire — with a laptop running the SDR# software, and runs through detecting and decoding a range of signals normally beyond the capabilities of the TV tuner. For the home automation fan, there’s a section on discovering and decoding devices which use the 433MHz part of the industrial, scientific, and medical (ISM) spectrum.
https://www.instructables.com/id/A-Software-Defined-Radio-on-a-Shoestring/
Tomi Engdahl says:
TEMPEST Comes To GNU Radio
https://hackaday.com/2020/05/14/tempest-comes-to-gnu-radio/
As we use our computers, to watch YouTube videos of trucks hitting bridges, to have a Zoom call with our mothers, or even for some of us to write Hackaday articles, we’re unknowingly sharing a lot of what we are doing with the world. The RF emissions from our monitors, keyboards, and other peripherals can be harvested and reconstructed to give a third party a view into your work, and potentially have access to all your darkest secrets. It’s a technique with origins in Government agencies that would no doubt prefer to remain anonymous, but for a while now it has been available to all through the magic of software defined radio. Now it has reached the popular GNU Radio platform, with [Federico La Rocca]’s gr-tempest package.
He describes it as a re-implementation of [Martin Marinov]’s TempestSDR, which has a reputation as not being for the faint-hearted. The current version requires GNU Radio 3.7, but he promises a 3.8-compatible version in the works.
An implementation of TEMPEST en GNU Radio
https://github.com/git-artes/gr-tempest
https://iie.fing.edu.uy/investigacion/grupos/artes/es/proyectos/espionaje-por-emisiones-electromagneticas/
Remote video eavesdropping using a software-defined radio platform
https://github.com/martinmarinov/TempestSDR
Tomi Engdahl says:
Understand the damaging effects of phase dispersion
https://www.edn.com/understand-the-damaging-effects-of-phase-dispersion/
Tomi Engdahl says:
Add More RF with MoRFeus
https://www.hackster.io/news/add-more-rf-with-morfeus-8e841fba8449
MoRFeus is a field-configurable wideband frequency converter and signal generator made for RF testing and hacking.