Noise performance of a Cartesian loop transmitter

The Cartesian loop transmitter is now a well-known linear transmitter architecture and is finding application in a number of mobile radio systems employing linear modulation technologies. In particular, systems utilizing /spl pi//4 DQPSK require a linear transmitter, and many emerging standards [e.g...

Full description

Saved in:
Bibliographic Details
Published inIEEE transactions on vehicular technology Vol. 46; no. 2; pp. 467 - 476
Main Authors Kenington, P.B., Wilkinson, R.J., Parsons, K.J.
Format Journal Article
LanguageEnglish
Published New York, NY IEEE 01.05.1997
Institute of Electrical and Electronics Engineers
Subjects
Applied sciences
Attenuation
Design methodology
Design optimization
Exact sciences and technology
Feedback
Land mobile radio
Multichip modules
Noise level
Performance gain
Radio frequency
Radio transmitters
Radiocommunications
Telecommunications
Telecommunications and information theory
Transmitters. Receivers
Mobile radiocommunication
Noise
Transmitter
Performance analysis
Power amplifier
System analysis
Linearization
Online AccessGet full text

Cover

More Information
Summary:The Cartesian loop transmitter is now a well-known linear transmitter architecture and is finding application in a number of mobile radio systems employing linear modulation technologies. In particular, systems utilizing /spl pi//4 DQPSK require a linear transmitter, and many emerging standards [e.g., trans-European trunked radio (TETRA)] provide applications for the Cartesian feedback linearization (CFL) technique. One problem with the CFL transmitter is that its output-noise performance is no longer dominated by that of the RF power module employed within it (as is the case in more conventional transmitter architectures). The use of significant degrees of attenuation, followed by a high level of gain, within the loop, means that the noise performance of the loop is significantly poorer than that of a conventional transmitter. There are a number of tradeoffs that are available to the designer of a CFL transmitter to aid in the optimization of the output-noise performance. This paper presents a derivation of the noise performance of a Cartesian loop transmitter and highlights the design methods that may be employed in order to optimize its noise performance. It also provides a comparison of the theoretically derived behavior with that of a practical transmitter operating in the TETRA (380-400 MHz) band.
Bibliography:ObjectType-Article-2
SourceType-Scholarly Journals-1
ObjectType-Feature-1
content type line 23
ISSN:0018-9545
1939-9359
DOI:10.1109/25.580785