antennabluetoothpcb-antenna
I'm doing a project with a Bluetooth device for the first time, specifically with a JY-MCU Bluetooth module:
As you can see, the antenna is on the green PCB, which is in turn soldered to a breakout board.
Does it matter what orientation the antenna is in? For example, I could set it flat on its top or back as shown in the above image, or I could also plug it in vertically.
Will changing the orientation change the receiver and transmitter distance?
There seems to be a remarkable lack of relevant on-web material. Maybe just hiding.
This looks highly apposite Design of New Multi Standard Patch Antenna GSM/PCS/UMTS/HIPERLAN for Mobile Cellular Phones with an interesting appearance
And tri-band !!!
GSM Dipole antenna - very informative
Designing a GSM dipole antenna
Commercial product.
LOOKS simple.
LOOKS good
LOOKs can be deceiving :-)
They say:
800/900/1800/1900/2100MHz
Omni Directional 1/2 Wave
Miniature 42 x 42 x 1mm
VSWR <3.0
RG178 Coax 50Ω Impedance
2-3dBi Gain (nominal)
Vertical Polarization
Admitted Radiation Power 1W
The free marvellous NEC RF software will probably do what you want.
Have a look here RF/Microwave Tools and here Tools and calculators - with RF writ large
If you have enough $ - Agilent ADS
The main rule for such antennas is not to have any metal part near them, be it the board copper or not. Or, if this is impossible, to have them as far as possible. If you look at the area of the module around the antenna, you'll probably see that there is no copper in any of its layers. Given that, and provided that you made a keepout area on all layers of your board under the antenna, the two choices that you presented are almost the same, with the one in which the module is up marginally better because it's a bit farther from the battery. But even then the result may have quite low performance, because you still have lots of metal areas near the antenna. No matter what is the chemistry of the battery, it'll most certainly be totally opaque to RF, so the better would be to "slide" the module to the left until the antenna is outside the board area and there's nothing below it.
Best Answer
Yes it does, in contrary to other answers. It's not an isotropic antenna and will have more gain in one direction than another. This affects transmission distance. Using the example shown in aloishis89's answer there is clearly a 10dB difference in antenna gain in one direction compared to another. Using the Friis Free-space formula for link loss: -
Link loss (dB) = 32.5 + 20 log(MHz) + 20 log (kilometres)
If the link loss was made 10 dB greater by misalignment of the antenna clearly this affects the distance that the receiver can be placed away from the transmitter. A 10dB increase in link loss can be "recovered" by shortening the distance between the two antenna to 31.6%