Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

New answers tagged

0

There is a similar connector that can connect the onboard antenna when there is no coax and disconnect the onboard antenna when the coax is connected. That would solve your problem without any soldering to change the configuration. See this link for a discussion on the topic.


0

This wave will return to the transmitter with a certain phase shift from which we can evaluate the distance between the object and the transmitter. No. The radar sends a pulse, and times the reflection. It's the round trip time delay that's used to evaluate the distance to the object. If you have a left-travelling wave and a right-travelling wave, then ...


0

Had a look at the datasheet. It seems you are supposed to let Abracon supply details to you when you use their optimization service. The datasheet is rather minimal on purpose. You make an area of the specified size on your board (or a sample with just minimal traces and the antenna pads,) send the whole shebang (together with a few hundred bucks) to ...


0

ok, One possible answer, yet no clear reason, so not really very well solved, but clears some things: I've now received a comment from one of my colleagues as well that, yes, that's how some of the antennas are mounted. Even though there's an evident short from feedline to GND due to the chip antenna pad, the internal construction of the antenna would ...


0

If used as specified the output power = Pin + 3dB . This means rather than rather than isotopic= spherical pattern, it radiates twice this power in one direction above ground plane or half of a sphere , usually in a toroidal (donut like) intensity 3D pattern with a null in the axial direction.


6

while discussing Micro strip antenna only electric field is explained It's because it's well understood that the magnetic part of an EM field can be deduced from the electric field part and vice versa. Hence, engineers usually only bother talking about one or the other. What I've just said applies to the far-field of the radiating EM wave. If we are talking ...


0

Are you within 20cm of the radios? Those warnings are generally in place as a defense against lawsuits, meaning if you did get sick they would say you ignored the warnings and so it isn't their fault. That doesn't mean that being within 20cm is dangerous, it just means they think if it was dangerous that being outside 20cm might be safe(er). How do they ...


5

A lot of people worry about health effects of electromagnetic radiation, and you'll find a lot of scaremongering misinformation on the web, but it is generally agreed by doctors and scientists that the electromagnetic radiation from WiFi equipment is extremely unlikely to cause any remotely significant risk of cancers. The World Health Organization says: ...


2

"Active antennas" include an amplifier to improve reception. This works well with things that only receive. GPS receivers and television receivers only receive. It is fairly easy to include an amplifier to make reception better. GSM has to transmit as well as receive. It is much more difficult to make an active antenna if you have to be able to transmit ...


0

What you are looking for is properly termed a 'GSM Repeater' and there are many on the market. These tend to be on the expensive side, and they may or may not be legal in your country. So, I would first check that a passive 'gain antenna' will not serve your purposes. Omnidirectional antennas are easily available up to 7dBi, and even higher gain is ...


-2

Ham License has variable steps and testing but GMRS does not. GMRS is 50W radio station authorization license. 70$ for 10years. DIY Application if you are capable enough to fill it out. Otherwise GMRS app/license runs 500-1000$ of you have a shop do it for you.


2

This is a good question. Yes, every changing magnetic field induces a current in a conductor going through that field. That's induction for you. Think about the most elemental antenna you can think of: the dipole. Just two sticks of metal, end to end. When these two metal sticks sum up to be half a wavelength, all the currents align in the antenna, sum ...


2

So: At your dish, there's a feedhorn. That feedhorn converts the focused waves (which are circularly polarized) from the parabolic reflector ("dish") to a wave in a (typically rectangular) waveguide with linear polarization. That waveguide is pretty short and ends on the PCB of your LNB, where there is a waveguide feed, which is essentially a purpose-...


1

Dipoles are linearly polarized. Most satellite signals are circularly polarized, this allows satellites to rotate, eliminates alignment issues on the ground (instead of horizontal and vertical linear polarization you would end up with n/s and e/w linear polarization, or whatever axis was used). Also, signals can get rotated when traversing the ionosphere ...


2

Monopole antennas are single wire antennas and are basically half a dipole antenna. They rely on a ground to most effectively radiate (like a dipole) but can still radiate without a ground. Think also about transistor radios tuned to FM - they use a telescopic antenna that is a monopole with a less than ideal earth plane. If a wire is passing current there ...


2

Certain antenna types like dipoles and microstrip patches are effectively leaky resonators. They support a standing wave at single frequency and have relatively narrow bandwidth (high Q), just like an RLC circuit. The same way an RLC circuit loses energy to the resistive element, antennas lose energy to radiation. At its resonant frequency, an antenna like ...


1

Based on the abstract, the authors seem to use the acronyms PEC and PMC to mean "perfect electric conductor" and "perfect magnetic conductor", respectively.


0

A quick search for this Molex “part number + Application note “ shows a variety of sizes each with a specific inductance , L with a series capacitor added to resonate at this NFC frequency. Bigger is better for range in the 10 cm + ballpark. Molex also have some with ferrite substrates that raises L slightly using a slightly smaller cap. The ferrite ...


1

A quick review shows that the Lant has complimentary design (first sentence on P.81 of the data-sheet). This is also true for a coil antenna such as the one you found from Molex. Short answer: Yes. Not as short: You should verify antenna parameters to understand whether you need to tune the antenna to your reader. The typical application example shows there ...


0

Can I use an external antenna 1462360001 from Molex in place of Lant The MFRC22 is a 32 pin chip therefore, any mention of an antenna is always going to be an external antenna i.e. the chip doesn't have an internal antenna. Regarding whether the Molex antenna is suitable, there is nothing in the data sheet that states it is used for 13.56 MHz so, without ...


1

I would like to know if the same trick can work with NFC readers No the same trick cannot work with near-field tags using aluminium foil. Aluminium foil placed close to the tag will act as a partially shorted turn of wire and reduce the magnetic field due to eddy current losses in the aluminium. However, you can purchase rubberized ferrite sheets that can ...


0

It all depends on the coupling factor. Different coil sizes for reader and tag will lead to a reduced coupling factor between the coils which will lead to reduced communication distance. The situation is worse for smaller reader and bigger tag antennas because in passive RFID coupling, it is the reader that powers the tag and this is often the limiting cause ...


1

After testing the actual setup, I was able to get a successful exchange between the smaller reader and the larger tag. Comparing the same tag on another, larger reader show that the smaller tends to have more erroneous transactions and the range is very limited, but I am still able to get valid transactions with a valid CRC.


Top 50 recent answers are included