Data converters

High-speed ADCs (>10MSPS) – RF sampling

What is RF sampling?

"RF sampling" is the technology of digitizing an RF signal with an ADC directly, without an analog frequency conversion to a lower IF (intermediate frequency) or baseband (Zero IF) before the signal is converted from analog to digital.

An RF sampling ADC can replace a radio signal path subsystem of mixers, LO synthesizers, intermediate frequency amplifiers and filters, and sometimes multiple ADCs, reducing bill of materials, cost, design time, size, weight, and power, while increasing the software programmability and flexibility of the system.

TI's latest generation of RF sampling ADCs can digitize signals at frequencies up to ~4GHz and at sample rates up to 4Gsps, addressing the needs of UHF/VHF/L/S-bands (IEEE) to cover a wide array of applications such as 3G/4G/5G wireless base stations, microwave backhaul, test, scientific, spectroscopy, military communications , radar and wideband software-defined radio (SDR).

RF sampling

Where is RF sampling Used?

An RF sampling ADC can replace the final (or only) frequency conversion stage in RF applications such as:

  • Software Defined Radio
  • RADAR/SIGINT/ELINT
  • Signal/Spectrum Analyzers
  • Cable Headend
  • Cellular Base Stations
  • Wireless Backhaul
  • Radio Astronomy
  • GPS/GLONASS/Galileo Navigation Receivers

RF vs IF/ZIF sampling

RF sampling can replace IF-sampling and ZIF-sampling architectures

Performance example

The following FFT plots are proof that the performance of RF sampling ADCs is achieving high levels of spectral purity and bandwidth

Performance Example

Integrated digital down converter

The inclusion of an integrated DDC (digital down converter) in the RF sampling ADC allows the processing of one or more narrow band signals of interest with reduced (decimated) data rates at the DDC output and interface to the DSP/FPGA, while providing the observation of a large bandwidth via a high sample rate ADC.

Integrated Digital Down Converter