CMOS RFICs: Benefits & Top Manufacturers

Introduction : CMOS RF Integrated Circuits (RFICs) are the undisputed kings of consumer electronics, powering the Wi-Fi, Bluetooth, and 5G transceivers in billions of devices worldwide.

What is a CMOS RFIC ?

CMOS is manufacturing technology used to build the digital processors inside computer and smartphone. An RFIC built on CMOS utilizes standard silicon transistors to process high frequency radio waves.

While standard bulk CMOS is used for highly integrated transceivers, the RF industry also relies heavily on a specialized variant called RF-SOI (Silicon On Insulator). In RF-SOI, a microscopic layer of insulating glass is placed between the silicon transistors and the silicon substrate. This prevents the high frequency RF signals from leaking into the substrate, drastically improving signal integrity, lowering insertion loss and making CMOS highly competitive for RF switches and antenna tuners.

Key benefits of CMOS in RF

Following are some of the advantages of CMOS in RF engineering.

1. Using CMOS multiple different logics can be placed on single SoC such as RF transceiver, ADCs, digital baseband processor and MAC layer onto a single, microscopic piece of silicon.
2. CMOS is manufactured in large semiconductor fabs on massive wafers (~12 inch). If wireless standard requires billions of units, CMOS is the only economically viable choice.
3. Advanced CMOS nodes are routinely used to design fully integrated 28 GHz and 39 GHz phased array transceivers for 5G mmWave smartphones. This has become possible due to high transit frequency of the transistor.
4. CMOS is efficient in processing digital algorithms. Hence it is used for massive digital processing right next to RF chain while consuming very low power (~micro-watts).

Key manufacturers of CMOS RFICs

Manufacturing Foundries

Summary:

It allows engineers to compress entire radio systems (e.g. antenna swith to digital blocks) onto a single, dirt cheap piece of silicon. Hence CMOS RFICs have made ubiquitous, everyday wireless connectivity a reality for billions of people.