The triple band feed horn project is targeting the increasing prevalence of Ka-band satellite payloads for broadband applications on satellite orbital slots that also provide TV services in Ku-band. The triple band feed horn specifically solves the requirement for residential Ku-band TV service reception and Ka-band broadband reception and transmission from one satellite, where previously spatially separated satellites had to be used to deliver these services at the same performance. This means that now space assets at the same orbital slot (either a single satellite or co-located satellites, usually from the same satellite operator) can be used to deliver these services to end-user households. While we currently see the main opportunity for the triple band feed horn with satellite broadband to land-based end-users, we envisage that the feed horn could also be of interest to mobility end-users (for example in maritime applications).
Due to the complexity of the feed horn and wide frequency range, very strong interactions or interferences occurred in every stage of the design, resulting in continuous re-tuning or re-optimisation of each part or sub-system.
The Triple Band Feed Horn enables satellite operators, broadcasters and broadband service operators alike to now use space assets at the same orbital slot (either a single satellite or co-located satellites, usually from the same satellite operator) to deliver their services to end-user households via a single antenna without power degradation as could be expected from other solutions such as a dichroic sub-reflector.
The Triple Band Feed Horn prototype has flanges to connect to standard off-the-shelf LNBs and transceivers. In addition it operates in the following frequency bands and polarizations.
- Ku Rx band from 10.7 GHz to 12.75 GHz
- Ka Rx band from 19.7 GHz to 20.2 GHz
- Ka Tx band from 29.5 to 30 GHz
- Dual linear polarization (V & H) in Ku band
- Dual circular (LH & RH) in Ka band
The complete triple band feed horn system can be broadly divided into four sections, the common feed horn section to both Ka- and Ku-band frequencies, the parallel waveguide section, where RF waves received from or transmitted to the feed horn section are combined or separated into respective signal channels. The sectoral waveguide section, where Ku-band waves propagate and finally the OMT and combiner section, where each RF signals are excited into or picked up from the waveguide wave modes.
The main project milestones were the Baseline Design Review (BDR) at which the initial simulated design was reviewed. The second phase of the project until the Final Review (FR) contained two prototype iterations to achieve the targeted performance.
During this project Global Invacom have developed a working prototype of a Triple Band Feed Horn, covering frequencies at 10.7 to 12.75 GHz (Ku Rx band), 19.7 to 20.2 GHz (Ka Rx band) and 29.5 to 30 GHz (Ka Tx band). The prototype has been successfully tested in a far-field antenna test range.