Table of Contents
International Journal of Microwave Science and Technology
Volume 2014, Article ID 396494, 11 pages
Research Article

High Power Combline Filter for Deep Space Applications

1ISRO Satellite Centre (ISAC), Bangalore 560017, India
2Department of Electronics and Electrical Communications Engineering, Indian Institute of Technology (IIT), Kharagpur 721302, India

Received 6 May 2014; Revised 3 July 2014; Accepted 25 July 2014; Published 14 September 2014

Academic Editor: Mirco Raffetto

Copyright © 2014 A. V. G. Subramanyam et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


An S-band, compact, high power filter, for use in the Mars Orbiter Mission (MOM) of Indian Space Research Organization (ISRO), has been designed and tested for multipaction. The telemetry, tracking, and commanding (TT&C) transponder of MOM is required to handle continuous RF power of 200 W in the telemetry path besides simultaneously maintaining an isolation of greater than 145 dBc to its sensitive telecommand path. This is accomplished with the help of a complex diplexer, requiring high power, high rejection transmit path filter, and a low power receive path filter. To reduce the complexity in the multipaction-free design and testing, the transmit path filter of the diplexer is split into a low rejection filter integral to the diplexer and an external high rejection filter. This paper highlights the design and space qualification phases of this high rejection filter. Multipaction test results with 6 dB margin are also presented. Major concerns of this filter design are isolation, insertion loss, and multipaction. Mission performance of the on-board filter is normal.