What Is The Difference Between A Patch Antenna and a Crosshair?

What Is The Difference Between A Patch Antenna and a Crosshair? - FPV Questions

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Joshua Bardwell Livestream Clips

Күн бұрын

Пікірлер: 16

@MrBumbles2 Жыл бұрын

VAS well worth the cost

@StantonLuke Жыл бұрын

MenaceRC PicoPatch is a great blend between the two - it’s a patch with a raised antenna patch. 25mW Range tested to 1.33km 60% increase in range over a 5db patch 20% increase in range over a 8db patch 38% increase range over the Invader patch (menace RC original patch) Reduced multipath propagation compared to 360 degree omni style receiving antenna’s.

@CAGreve1231 Жыл бұрын

A patch antenna is a resonant microstrip. You don't need a PCB material for a Patch. Take L-Com's patch or the "Fast Patch" from my RCGroups tutorials of 12 years ago. And believe it or not, PCB manufacturing isn't as precise as you'd think. The thickness is a killer... especially for a patch antenna. The killer of the PCB based patch is that with a PCB the substrate slows down the speed of propagation which reduces the element size. The reduction in element size reduces the amount of voltage stress which is absorbed by the antenna which reduces the efficiency. A patch antenna with an air substrate can be just as efficient as a Crosshair. The advantage of a Crosshair is the radiation plot is superior to a patch. They boast a very high axial ratio (ability to rotate a signal) and they also aren't affected by ground planes (like the physical ground beneath your feet) as much.

@soy_leche Жыл бұрын

"The thickness is a killer... especially for a patch antenna." - does this mean something like very thin gold foil would be a better antenna?

@CAGreve1231 Жыл бұрын

Thickness of the substrate is the problem, not so much the conductive material used for the element

@soy_leche Жыл бұрын

@@CAGreve1231 Ohh, thanks for the reply

@feel_fine Жыл бұрын

Hi JB, a little correction. What you explained as patch antenna is basically a PCB antenna (there are plenty of different design of PCB antennas apart from patch, like slot, F-inverted, monopole etc.). Patch antennas may also use a special rf ceramic for substrate with proper dielectric properties like for example 99% of gps patch antennas do. So, what you mentioned as cons to patch antennas is basically applied to PCB antennas as manufacturing type, not Patch as design type. Thanks anyway for your videos.

@Inertia888 Жыл бұрын

I was wondering about ceramic GPS antennas. Thank you. Now, would a GPS antenna be more, less, or equally efficient if it used an air gap, instead of a ceramic substrate?

@Mr.Laidukas Жыл бұрын

Patch antenna can be made not only from PCB, copper can be suspended in air on standoffs and it will be as efficient as crosshair. Its just that manufacturer chose to use inefficient and lossy PCB substrate to lift active element above reflector for simplicity of manufacturing process. Both antennas are active elements lifted above reflector surface. It is just that crosshair antenna need to be lifted in higher distance and it is no more practical to use PCB material to suspend active elements.

@FpvFunFly 6 ай бұрын

What do you think about the 1.3 GHz Arkbird crosshair antenna?

@gsegallis 6 ай бұрын

"A" for effort and for having the guts to attempt to address antenna black magic that most of of us engineers try to avoid (probably should have left this topic alone, LOL) Nope... efficiency isn't the discriminator. And any impedance antenna can be matched using a tuning circuit/transformer. A patch antenna can achieve an SWR of near 1.0 just like other configurations. Also, one antenna you you showed was a circularly polarized antenna, which, afaik can only be implemented on a patch antenna using two feeds (where other configs, like a cloverleaf/skew planar can do it with one). Patches typically have an H and V pole, or include a phase shifter combining the two poles of the "patches", which is still 2 feeds wrt the antenna. Besides cheap to manufacture, patches are also near indestructible.