For the past two weeks or so, I’ve been working on constructing the Taylorator. The Taylorator is a piece of software which allows me to flood the FM broadcast band with Taylor Swift’s music. No matter where you tune your radio, you will only be able to listen to her!

What do I mean by flooding the FM broadcast band? Well, in Canada and the US (and maybe other places too), the FM broadcast band spans 88 MHz – 108 MHz. You can’t broadcast wherever, though. Stations will only appear on odd-numbered frequencies, like 88.1 MHz, 94.5 MHz, 107.3 MHz, etc. There’s a technical reason for this – every FM broadcast takes up about 150 KHz of bandwidth, and spacing the broadcasts like this allows for an extra 50 KHz of wiggle room.

This also works out to 100 different frequencies that we need to populate (with 100 different songs). So, how can we accomplish this?

SDR, or Software Defined Radio, is a paradigm where you do most of your signal processing in software, and then a relatively dumb piece of hardware creates a real-world signal from this virtual signal. It works similarly to a sound card. It takes in a series of samples, and spits out a waveform that matches these samples.

One important difference between a sound card and an SDR is that a sound card takes real-valued samples, and an SDR takes complex-valued samples. That is to say, each SDR sample can be presented as a single number a + bi, where a and b are real numbers. This is primarily done because it cuts the required sample rate in half, as it allows for negative frequencies. On the hardware side, this results in a simpler design, which lowers cost.

FM modulation in software
FM modulation follows a pretty simple formula. Basically, y_n = e^(i*pi*sum(x)), where y_n is the output sample, and x is the input audio stream up until this point. (

Teledyne e2v showcased its EV10AS940, the company’s latest advanced 10-bit broadband data converter—a part of its push into software-defined microwave technologies. Conventional radios still use heterodyning to mix two signal frequencies in a nonlinear mixer. Moving to high-bandwidth direct-conversion devices enables significantly simplified, software-defined receivers with frequency agility. In a major front-end architectural change, the solution employs single-ended design rules for the clock and signal lines; thus, frequency-dependent baluns can be eliminated.

A 0 – 32MHz FPGA based Software Defined Radio (SDR) built assembling ready modules -> quite cheap and easy to build

What you’ll learn:

Characteristics of transceivers that combine analog, digital, and mixed-signal components, such as SDR, RFSoC/SoC, and DFE technologies.
Basics of an SDR and RFSoC/SoC.
The advantages/disadvantages of using an SDR with discrete integrated circuits and other components versus a RFSoC/SoC.

Transceiver devices are ubiquitous in today’s highly connected world. Various transceivers exist for a wide range of applicability, which often combine analog, digital, and mixed-signal components. This article focuses on software-defined radio (SDR), radio-frequency system-on-chip (RFSoC/SoC), and digital front-end (DFE) technologies, all of which work as transceiver devices with embedded digital-signal-processing (DSP) capabilities.

Discussed are the advantages/disadvantages of using an SDR with discrete integrated circuits (ICs) and other components for the analog domain, as opposed to RFSoC/SoC (or other fully embedded radio front ends).

Here we take a look at the Q900 Version 3 Ham Transceiver which covers all ham bands from 160m up to 70cm.