Wireless and Digital Services

A Radio with No Analogue Parts?

By Monty Barlow - Last updated: Wednesday, November 26, 2014

We have built a working radio transmitter with only digital parts, code-named Pizzicato. No analogue filters and mixers. No exotic Gallium Arsenide chips. Just good old regular digital logic. This is a big deal, and no one has done it before.

Despite the buzz around an increasingly digital world, so called ‘Software Defined Radios‘ today have one foot firmly in the analogue past. Mobile phones, Wi-Fi access points, police radios and Bluetooth headsets all use analogue circuitry to handle radio frequencies.

So what have we done differently? New mathematical tricks mean we can compute multi-Gigabit/second, digital waveforms in real time without a supercomputer. Software can shape and control this waveform, making almost any signal imaginable at any frequency.

If we’re going to get high-speed broadband to every mobile phone in the world we’ll need lots of tiny, high performance radios in those phones. The radios will be squashed together in a way that analogue just doesn’t tolerate. Whereas a Pizzicato-like digital radio can follow Moore’s Law to smaller size and lower power consumption.

100 billion Internet of Things devices will need to continuously scavenge for scraps of spectrum in which to operate. Purely digital radios will be unfazed by this new dynamic way of operating.

Pizzicato is the first glimpse of a future of ultra-flexible, ultra-small digital radios. It’s early days yet, but I think we’re at a turning point. From here on in, radio design is going to change very rapidly.