Quadrifilar antenna design and interference
Quadrifilar antenna design and interference
(OP)
Hello everybody this is my first post, so nice to meet you all!
I am studying the use of 137mhz QHA antennas on the sides of a satellite. Unfortunately my experience with antennas is quite limited, so I would love if you could give me some insight!
First point is: I am using NEC2 and got the following results. Does this seem realistic to you?



Second point is: I would like to irradiate in different directions, so the plan is to place 3 QHA on different sides of the satellite. Do you think there are any constrains on this? Let's say I place them 2m apart (wavelength is roughly 2m), would that be ok?
thanks for help!
Romeo
RE: Quadrifilar antenna design and interference
If you drive multiple antennas at the same time, then it'll act as a phased array to some degree. Unless the patterns are truely non-overlapping.
QFHA are a good choice for CP and broad low gain pattern.
Scale implies this isn't a tiny cube sat.
RE: Quadrifilar antenna design and interference
Thank you for the feedback! It will be pointing down, but there is a need for redundancy, therefore the 3 antennas.
How can I quantify whether antennas are truely non-overlapping?
Thks
Romeo
RE: Quadrifilar antenna design and interference
Another approach is to use voting for the receiver, and intelligent switching for the transmit.
In other words, select the best antenna.
This may assume that the transmissions are not continuous.
RE: Quadrifilar antenna design and interference
https://www.ersantenna.com/
RE: Quadrifilar antenna design and interference
RE: Quadrifilar antenna design and interference
TTFN (ta ta for now)
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