European Space Agency

Development of an EQM for a Ka-Band Preselect Filter


The goal is to develop and test an EQM for a Ka-Band Preslect Filter. The activity also includes:

-          Electrical design, verified with a breadboard.

-          Tunability and the possibility of a tuneless filter will be checked.

Manufacturing and qualification tests of an EQM unit to demonstrate the simulated performances.


From electrical point of view the filter is challenging for RYMSA because of the high selectivity required as well as the high level of rejection required near the band pass. In addition a low level of insertion losses is demanded.

Additionally the mass and envelope must be maintained within very demanding values. A compact design will be a must.


The commercial opportunities for this new development are generated by the increase in the use of higher frequency bands (Ka-Band) due to the expansion of the average bandwidth available on a comsat. Growth results from more efficient electronics on the ground and on satellites, which makes it easier to share the spectrum.


The filter is used in the payload in order to filter the up-link corresponding to the commercial band defined within Ka-Band. Then, the chosen operating band is from 27 to 29.1GHz. The filter is able to provide a high level of rejection up to 61GHz, with a competitive envelope and mass figure (40g).


A first stage to consolidate mission needs, and get the requirements at filter level was performed.

A second stage is dedicated to a the electrical design of the unit, and confirmation of the simulated results by means of a breadboard.

Then, a dedicated mechanical analysis is performed, taking into account that the unit will be manufactured in two halves by milling, and its joint by means of a high-pressure flange.

Then, an EQM is manufactured and tested at qualification levels, providing successful results and confirming the electrical and mechanical validity of the chosen option.

Current status

An EQM was manufactured and successfully tested confirming the foreseen results at design phase.

Status date

Friday, October 28, 2016 - 09:24