On-board Antennas for LV2
We're flying radios on a rocket. So, the first thing we need to know, is:
- What's our link budget?
And then, how do stop our antennas from ripping off at Mach 3? To answer that question, we looked into two types of antennas that are integrated into the airframe:
We chose to go with the cylindrical patch antennas (CPAs) because they seem like the "right thing", and our slot antennas were never much good and didn't have the propagation pattern we wanted.
The problem with CPAs is that the circularaly polarized commercial CPAs are tens of thousands of dollars. One quote we got was $18,000 per antenna. Whoops, no thanks. So, we decided to home brew. Since we're antenna amateurs, we chose the easy route and designed linearly polarized CPAs. Those of you who Know Antenna Design please contact us because we really could use the help (!).
We have three CPAs we need to integrate into LV2:
- 2.4 GHz bidirectional telemetry system (currently 802.11b)
- 1.5 GHz GPS receiver
- 1.3 GHz amateur TV broadcast system
For our linearly polarized cylindrical patch antennas, please see:
On the ground, we've decided on right-hand circular polarized end-fire monofilar helixes. See:
- For our old thoughts and problems with antenna design, please see our AntennaLetter.
- BROKEN:Note that attached below is the excellent rendered drawings from Brian on the Avionics Module's mechanical specifications.