Bluetooth Antenna Design.pdf

That was an interesting process as well and probably deserves its own blog post. We were able to pass with only minor corrections and dropping the tx power a couple notches.

An antenna with higher gain will be more directional. You hook it up to your system in our case, formalin pdf our antenna and it uses a variety of techniques to determine the impedance of the network. This will change the properties of your antenna!

Loop antennas are inherently less susceptible to dielectric losses or detuning than dipoles or monopoles due to the near fields being predominantly magnetic instead of electric. Once you calibrate to a certain shape of the cable, test your antenna with that same shape. An omnidirectional antenna with low gain e.

Bluetooth antenna design.pdf

However, the amount of absorption really depends on frequency of operation. This is, however, an expensive exercise, so do your best to avoid it.

This helps explain why some products perform better than others. Try to at least keep the antenna a few feet away from any large metal objects, and note how much the impedance changes as a function of orientation. If you make the antenna shorter, your resonant frequency will have a shorter wavelength, and therefore a higher frequency.

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Bluetooth antenna design.pdf

The width of the feed line does. Notice that the output of the chip is actually differential but the matching components convert it to a single-ended output. The plastic case and battery. These parts can be used to change the impedance of the antenna so that it matches the impedance of the chip. External whip antennas also known as ducky antennas are typically a bit larger, but are a good choice if you have the room.

These have good performance, the only drawback being their physical size. Basically a smith chart is a convenient way to picture real and complex impedances on one graph.

Bluetooth antenna design.pdf

Thank you so much for posting this great methodology! Everything can be done by varying the length of the tail. This is accomplished by slicing your antenna to various lengths with an exacto knife.

Important thing to remember- everything surrounding your antenna will affect the performance. There were hiccups along the way, but we were able to bring the output power down a bit to pass the tests. As frequency decreases, water becomes less lossy. For more consistent performance, use a ceramic or thin-film inductor to help increase the impedance bandwidth at the expense of additional loss.

Wireless Modules Antennas and IoT Platforms

Also email with questions if you run into problems. The downside to wire antennas? Does your Antenna have to be directional? So cutting your antenna shifts it up in frequency.

Nice to see mightyohm here too, I read his blog. Keep in mind the shape of the cable attached will affect your results, so calibrate it with that in mind. This means we only have one antenna trace that couples with ground. Our chip and antenna have characteristics that define their impedance.

AppCad is a great and free tool from Agilent. Advanced Circuits will sometimes etch an order number into the copper on your board.

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Single Ended vs Differential

However, increasing frequency also means more antenna gain can be realized for a given antenna volume. Some great antennas can have crappy impedance matches. Lower-frequency waves will generally propagate through materials more easily than higher-frequency waves. Tuning an antenna or changing the matching network that feeds it can affect the performance of the antenna in terms of gain and directivity.

See the below picture for those dimensions again. Rational Theme by SketchThemes. Web page addresses and e-mail addresses turn into links automatically.

High-Q inductors do have less loss than their ceramic or thin-film counterparts, and will provide lower transmission losses when using matching networks. To do this I had to drill a small hole through the board where the feed line began. However, I think you can get by with an F Antenna, and only building one. Full antenna before it gets cut. Then you can try different sizes easily.

Dipole antennas are balanced structures and thus have less radiating currents on coaxial-cable shields. Chip-antenna performance depends a lot on ground-plane size. The amount of power received is directly proportional to the effective aperture. Every network of components has a real and complex characteristics which define their impedance.

Bluetooth antenna design.pdf