Title
A New Quadrature PWM Modulator With Tunable Center Frequency for Digital RF Transmitters
Abstract
State-of-the-art quadrature-type modulators for all-digital radio-frequency (RF) transmitters operate optimally at an RF center frequency (fc) that is a fraction of the modulator switching rate. This is a major limitation if the modulators of this type are to be used in multichannel transmitter systems. In this brief, a novel quadrature modulator based on pulsewidth modulation with controllable in-band distortion is presented, which permits continuous adjustment of fc in digital domain. In addition, distortion generation related to digital upconversion of pulsed baseband signals is studied, and suitable compensation methods are given. The performance of the proposed modulator is compared with those of previously published encoding methods in terms of reconstructed RF signal quality and computational complexity. The evaluation results suggest that significant improvements in signal band distortion can be expected with a computational load suitable for real-time reconfigurable hardware realizations.
Year
DOI
Venue
2012
10.1109/TCSII.2012.2222834
Circuits and Systems II: Express Briefs, IEEE Transactions
Keywords
Field
DocType
computational complexity,modulators,pulse width modulation,signal reconstruction,transmitters,RF center frequency,computational complexity,computational load,digital RF transmitters,digital radiofrequency transmitters,digital upconversion,modulator switching rate,multichannel transmitter systems,pulsed baseband signals,pulsewidth modulation,quadrature PWM modulator,realtime reconfigurable hardware realizations,signal band distortion,signal quality reconstruction,tunable center frequency,Pulsewidth modulation (PWM),radio-frequency (RF) transmitter,sigma–delta modulation,software radio,switched mode
Baseband,Computer science,Pulse-frequency modulation,Pulse-width modulation,Modulation,Electronic engineering,Radio frequency,Analog transmission,Amplitude modulation,Electrical engineering,Distortion
Journal
Volume
Issue
ISSN
59
11
1549-7747
Citations 
PageRank 
References 
2
0.43
5
Authors
3
Name
Order
Citations
PageRank
Henri Ruotsalainen121.44
H. Arthaber2165.91
Gottfried Magerl322.12