That second image shows a feed where you would expect it. It's a bit hard to see on all of the elements, and it's better to look at the high resolution original image. But they're definitely center fed.
Specifically, see https://commons.m.wikimedia.org/wiki/File:Chernobyl_Exclusion_Zone_Antenna_hnapel_22.jpg and https://commons.m.wikimedia.org/wiki/File:...
This is a cage dipole antenna (or an array of cage dipoles to be exact). It works just like a dipole, but has a wider bandwidth. The thicker the dipole, the wider the bandwidth.
RF does not care if the conductors are hollow cylinders, solid surfaces, cages or mesh as long as size of the "holes" is signifficantly smaller than the wavelength (that is also why ...
Is it possible to transmit two different frequencies with certain bandwidths (say, 2.4GHz and 5GHz) with a single antenna, SIMULTANEOUSLY ?
Yes. Your smartphone typically has a combined 0.9/1.8/2.3/2.6 GHz LTE (for Europe) + 2.4 GHz Wifi/Bluetooth antenna system, and you can use WiFi simultaneously to LTE, so yes.
If yes, will there be multiple seperate ...
As far as I know, this effect has nothing to do with antennas and electromagnetic waves, unless you consider capacitive coupling as an antenna effect (which is unusual). Here is the complete explanation:
If you are sufficiently close to an electric wire connected to the main, there exists a small capacitance between the wire and your body. The closest you ...
JRE's answer has already identified that the connector on the Nordic board is a switch type, so none of these examples have both antenna options connected at once.
As to the other part of your question - why can't both be connected at once - the answer is impedance matching.
The integrated antenna will be designed to present a particular characteristic ...
I took a look around the Nordic documentation.
You don't need a jumper on the Nordic board because the RF connector it uses has a switch.
The connector is of SWF type (Murata part no. MM8130–2600) with an internal switch. By default, when there is no cable attached, the RF signal is routed to the onboard PCB trace antenna.
Do you really need a satellite dish to communicate with satellites?
No, if that were true, your phone's GPS would be rather unwieldy, wouldn't it? And satellite phones would be pretty impractical. (Satphones predate modern smartphones solidly.)
All that a satellite dish is an antenna with a very high directive gain. So, if your link budget says you don't ...
The short answer no - we are trying to match the output impedance from the chip to the antenna for maximum power transfer (usually 50 ohms)
As you seem to be a beginner, I strongly recommend you to read this short guide, it's awesome.
I've matched antennas with this guy and just an ...
Can I place GPS/GSM modem directly below GPS antenna or should I move
modem to the opposite side of PCB as much as possible? (I worry that
there will be GSM antenna traces directly below GPS antenna).
In many cases manufacturers recommend removing the ground plane beneath the GPS antenna, if this is the case placing anything else underneath the antenna ...
The best answer will be to follow the PCB layout guidelines suggested by the manufacturer of the modem module and your patch antenna. They will definitely have a whitepaper or application note about this.
If Qualcomm or Murata has a reference layout that would be a good starting point - it appears you have this. Generally you want to use 50 ohm routing for everything. Use microstrip with guard grounds surrounding it, as shown in the reference.
"satellite dish" is not a proper name. Proper name is parabolic antenna. There is nothing special about antennas used for communicating with satellites. It is just antenna for some frequency (or range of frequencies) and with some specified gain.
Satellites are far away so you need antenna with pretty good gain. You don't necessary need a parabolic ...
Connect the antenna port to the VNA port, measure S11.
You will want to ensure that there are no RF reflectors within sight of the antenna. This could be done by pointing it at the sky, out of a window, or at an RF absorber. Any signal reflected back to the antenna will appear as a returned signal at the antenna port, and so alter your true S11 measurement.
So what is the purpose of that metal layer ?
The metal layer is fundamental to the operation of a patch antenna. Patch antennas use a ground plane and that is what it is.
Bottom of the ceramic patch is fixed to ground plane on the top of PCB
through adhesive. So there is not contact of metal layer (which is
there at the bottom of ceramic patch) to ...