27 votes
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What are these uniform traces that extend to the board edge?

They are almost certainly part of a panel test fixture. Certain traces of each board on a manufacturing panel are brought out probably to a header on the outside edge where a tool is connected to ...
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  • 20.2k
24 votes
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How does a chip antenna work?

Dielectric resonator antennas, commonly referred to as chip, work by creating a standing wave of electrical field of a given frequency. Technically, they are cavity resonators where the cavity between ...
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24 votes
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IC on Digikey is 5x more expensive than board containing same IC on Alibaba: How?

Digikey sources their parts from the manufacturers and adds a retail mark up. The alibaba seller takes remnants from someone's production run (or possibly salvaged parts, or if you're unlucky ...
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  • 26.6k
23 votes

How does a chip antenna work?

To discuss the manufacturing and structure of chip antennas, consider first some images of antennas with obvious metalization patterns: From Mitsubishi Materials, the AM11DP-ST01*: There's a ...
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  • 2,788
18 votes
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Can a screw hole in between PCB antenna reduce efficiency significantly?

If the hole is empty and is not metalized, then it won't affect the performance of your antenna. If the hole is meant for mechanical fixing, use plastic screws. Metal screws might de-tune your ...
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14 votes
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What is the purpose of the elements of this antenna?

It seems to be a patch antenna array, analogous (among many images you could find googling around) to this one: Patch antenna arrays are a special kind of microstrip antennas. You can find many ...
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10 votes

Why can't you put a plane under a trace antenna?

An antenna converts a low impedance transmission line (from the chip or also via a coax or stripline) to a high impedance at the end of the antenna. The high impedance is to suit the impedance of free ...
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  • 378k
9 votes

How to design a 10GHz PCB antenna

First of all is it possible to create 10 GHz wave on a PCB? Any clue on how to do something like, regarding the circuitry? If by "creating" you mean propagating and/or radiating, the answer is yes. ...
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  • 5,621
9 votes

IC on Digikey is 5x more expensive than board containing same IC on Alibaba: How?

I would say that they are probably counterfeit,this is a well known problem when buying from china, you cant be sure that they are original unless you are buying from a trusted chinese supplier. Most ...
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8 votes

PCB Ground Pour, Crosstalk and antennas

all lines are single ended (like UART, SPI, I²C, etc.) and may have transition times of 1~3 ns. This is where you went wrong. I2C and UART run at a few MHz at the fastest. SPI can be run at maybe 10 ...
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  • 121k
8 votes

How can I make Bluetooth (2.4 GHz) reception area narrow and controllable?

Neither will work. If you build a metal case with a narrow opening, you'll have an even wider beam; the smaller the aperture, the larger the beam. It's practically impossible in this form factor to ...
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7 votes
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PCB Ground Pour, Crosstalk and antennas

is whether "fingers" A, B, D and E should be removed or perhaps they contribute to reducing crosstalk between the tracks. They should be removed because as is they do not really help and quite ...
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  • 11.5k
7 votes
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50Ω Impedance Matching with Signals Through Vias

However, what happens when the 50Ω traces hit a via? The via can act as a capacitive or inductive discontinuity in the transmission line. It will make at least a small reflection. Below 1 GHz, this ...
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  • 121k
7 votes
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How do ZOR antennas work?

"ZOR" is a complicated way of saying "electrically small" or "electrically short" resonant antenna (or antenna-array.) It's like having a CB-radio resonant base-load, but without any whip-antenna. ...
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  • 10.4k
6 votes
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Does the orientation of a Bluetooth antenna affect the transmission distance?

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 ...
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  • 378k
6 votes

Does the orientation of a Bluetooth antenna affect the transmission distance?

Edit: I was wrong, it can. Here's a picture of a similar antenna: And here's it's radiation pattern: The radiation pattern is a polar plot of the relative gain of the antenna at each angle. As Andy ...
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  • 1,648
6 votes
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How does a cube sat communicate with ground station with a 1w antenna

Here's how it works but a couple of factoids first: - According to this source, the most common frequency of transmission is 437 MHz Antenna gain\$^1\$ for a 1m dish is about \$0.5\cdot\dfrac{(\pi D)^...
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  • 378k
6 votes
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Preferred balun location? (Are differential microstrips preferrable to single-ended?)

All else equal, the differential traces will radiate less. This is because their opposing electric fields cancel for distances "far" away, with "far" being relative to the spacing of the traces. Less ...
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  • 55.3k
6 votes
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Help to understand/ explore small sized 3G and GPS Antenna Design

These things are all PIFA (planar inverted F) antennas. They all perform exactly the same, though they have to be carefully designed to fit into the enclosure and have the correct resonances. The ...
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6 votes

Why can't you put a plane under a trace antenna?

It's not that the plane will block transmission in one direction, but that it will absorb much of the power you put into the antenna, and also greatly change the antenna characteristics. The plane is ...
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6 votes

Getting started with Qualcomm reference designs

As someone who has been in the electronics sales and distribution world for a couple years now, I can say from experience that the majority of mobile handset chipset suppliers such as Qualcomm have ...
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6 votes

Difference between Antenna and Filter

Your assumption seems to be that filtering only one time is enough. That might be true but it might also not be true, it depends factors like: How much filtering outside your band of interest is ...
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  • 78.7k
5 votes
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Possibility of an extremely directional antenna

Your requirements will never be met. A dish antenna is the best for providing focus and if you looked at voyager II, it used a 3.7 metre dish at about 3 GHz. This would give a 3dB half-beam-width of ...
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  • 378k
5 votes

Antenna Design for specific directions

Additional specifications as clarified by "tman" Signal is not expected between 75deg and 90 deg and also between 0deg and -90deg elevation, and rejection in these sectors is not explicitly required. ...
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  • 12.2k
5 votes
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What module to look for if I want to tell if there's Wi-Fi in the air?

Regular 802.11 Wifi networks use something called a beacon frame to transmit all of their "housekeeping" information. This includes info like the SSID, the current time, and the supported data rates. ...
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  • 3,737
5 votes

Will this PCB trace GSM antenna be affected by EMI?

Apart from EMI issues, I have a hard time believing that this will work at all. Is there a reference design available for something similar? From what I would guess (I'm not an antenna specialist at ...
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  • 7,707
5 votes
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ESD Protection with no grounding

Your internal ESD devices will still take the discharge current themselves instead of letting it through to the sensitive MMIC input node. This assumes that there is some charge built up between the ...
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5 votes
Accepted

Function of solid plane in the NFC antenna

These antennas are from NXP evaluation boards. These metal parts lower the field-strength output because of the induced eddy currents. They also detune the antenna and the matching network quite a ...
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5 votes
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Accidentally connected a GPS antenna to a cellular connector and a cellular antenna to a GPS port. What can go wrong?

Looks like you are using an active GPS antenna which certainly means it has a LNA built-in. If you are setting-up the modem in GSM mode, at higher transmit power (if I recall correctly can go up to +...
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  • 916
5 votes
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Do I need to solder for activating PCB antenna on this ESP32

Looks like the jumper is there to select either the PCB antenna or the UFL connector. As we can see from the image in red, the default is the UFL connector as there is a 0R resistor connecting the two ...
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