PVFlyer said:
Hi Will, My assumption is we never fly P2V below us, unless we go to top of a hill and flying down hill.
Apparently, I guess the low gain patch antennas residing in Vision camera RF pattern covering 1/2 sphere (1/2 left & 1/2 right). Both left/right patches in the camera form a 360-degree complete sphere-like RF pattern. Based on the assumption, we waste upper 50% RF power radiating to the sky.
Are you able to design a 1/4 sphere-like CP antenna, while both left/right antennas would then cover 1/2 sphere below P2V. If this is feasible, we can push more RF gain below P2V and eliminate redundant RF radiating to the sky.
On the other hand, I may make a simple reflector covering the camera with aluminium/tin foil.
Just a few thoughts.
Hi there , well they did a pretty GOOD job AT DJI producing the antennas compact in the camera, when we add a SP for example
the RF pattern will be a big dome under the P2V ( mounted upside down) this does not change from LHCP to RHCP either its still LHCP, I did a video demonstrating this on the channel
A few months ago after looking at the DX8 RC transmitter we measured the output and it showed around 45 mW, so we then did a mod to it ( similar to what we are doing to the P2V) and then re tested , using the exact same BH+ we designed and the range jumped to over 6.4 kM !! thats a record for a DX8 with just 45 mw. see video here
http://www.youtube.com/watch?v=UdF8oEsbyJU
we have now redesigned the antenna for the PV2 and P2 , the main thing is reducing the weight mainly the performance is the same.
With the P2 version we can use the BH Micr 2.4 GHz for RC control instead of video and use another channel ( 1.3 ) would be the best bet here ) and then the BH+ 1.3 GHz , that would put the P2 in max range with the only limit is the
battery power
Also we did the same thing to the 9X and 9XR with the FRsky ( same antennas again ) and on tests the 9X ( measured at 65mW) went to a range of over 11kM !! that's 2.4 GHz with just 65mW , you can see the actual test here .
http://www.youtube.com/watch?v=zcbAVAgjkaY
all this
is fact and
proven by us in the tests, So transferring the gains to the P2V and the P2 would produce the
same results
You are quite correct 'make the rf go where you want it to' instead of out in all directions.
Another technique I devised is call reverse antenna tracking , in this mode a beam like the BH+ say 5.8 GHz is fitted to a copter
and mounted on the camera gimbal , since these hi end hexas have POI ( point of interest) it can work out the direction and angle to point the camera AND the antenna back to the GS, when we combine this with a BH+ at the ground station we have a
very very efficient link , using say 12dB on the copter and 14 on the ground would give
stunning results. I have tested this and achieved
5k with just 25mW. these work and the FPV community is
going to benefit from it and the development on work carried out by Horizon FPV