Ultrawideband RF-IQ Modulator Using Segmented Nonlinearly Scaled RF-DACs and Nonoverlapping LO Signals
Journal article, 2023

A wideband Cartesian in-phase and quadrature (I/Q) modulator based on dual 10 b RF-digital-to-analog converters (DACs) is presented. Nonoverlapping local oscillator (LO) signals and a segmented nonlinear scaling with scaled unit cells contribute to a high linearity and allow for a low-complexity digital predistortion (DPD). Unit-cell flip-flops (FFs) and a balanced clock distribution enable a high sample rate with little skew. Out-of-band emissions are reduced through drive-slope control of the data-switch inputs. The modulator, implemented in the 22-nm fully-depleted silicon-on-insulator (FDSOI) CMOS, operates between 20 and 26 GHz with a peak sample rate of 11 GS/s. It has been used to demonstrate the transmission of a 64-quadrature amplitude modulation (QAM) single-carrier (SC) signal at 13.2 Gb/s, a 256-QAM SC signal at 7.33 Gb/s, and an orthogonal frequency division multiplexing (OFDM) signal comprising four aggregated 400-MHz 64-QAM channels with an error vector magnitude (EVM) of 6.43%. These results demonstrate the potential of the proposed modulator for the realization of ultrawideband transmitters in high-performance millimeter-wave (mmW) systems.

Wideband

Codes

nonlinear scaling

OFDM

nonoverlapping local oscillator (LO)

Jitter

Clocks

Harmonic analysis

RF-digital-to-analog converter (DAC)

IQ modulator

CMOS

Modulation

Author

Victor Åberg

Embedded Electronics Systems and Computer Graphics

Christian Fager

Chalmers, Microtechnology and Nanoscience (MC2), Microwave Electronics

Rui Hou

Ericsson

Lars Svensson

Embedded Electronics Systems and Computer Graphics

IEEE Transactions on Microwave Theory and Techniques

0018-9480 (ISSN) 15579670 (eISSN)

Vol. 71 5 1899-1910

Subject Categories

Telecommunications

Signal Processing

Other Electrical Engineering, Electronic Engineering, Information Engineering

DOI

10.1109/TMTT.2023.3237713

More information

Latest update

3/7/2024 9