Compact Tunable IF Filters

The objective of the activity is to develop and evaluate a compact filter with the capacity to tune the bandwidth for flexible converters.

Bandwidth, frequency and power reconfigurable payload architectures are currently under development by major satellite manufacturers. Today's fixed bandwidth filters are a major bottle neck in such systems and have led to the implementation of reconfigurable filters. These new reconfiguration scenarios require flexible converters and, hence, flexible filters to be accommodated after the down/up conversion. A conventional approach is to include a switchable filter bank which, for advance reconfigurable payloads, implies an increase in the number of filters with the corresponding size increase.This activity aims to study new reconfiguration concepts in order to provide bandwidth flexibility to the IF filter. A second goal is to reduce the size whilst the insertion loss variation, group delay variation and rejection remain in line with the standard solution. Due to the position of these IF filters inside the payload diagram, an increase of absolute insertion losses can be tolerated. Pre-distortion and lossy filter theories have been supported in previous ESA activities. These techniques enable the use of lower Q-factor materials and/or reduce the size of the component. Therefore, new bandwidth reconfiguration techniques able to cope with methods to achieve the required compactness shall be designed, developed and tested. Solutions based on filter-banks shall not be considered in the frame of this activity. In this study, a filter switchable for at least 3 bandwidths will be designed, manufactured and tested.