IoT M2M Times - IoT antenna designs

Contents of this edition

The first edition of the IoT M2M Times was dedicated to the topic of antennas. The fifth and last edition in 2021 will once again focus on the topic of antennas. Antennas are the key to success in any IoT project.

1. Do it yourself PCB antennas
2. Semi-automatic PCB antenna generator
3. Antenna design training in 2022
4. IoT antenna designs in practice (e.g. Bluetooth AoD indoor tracking)

Do it yourself PCB antennas

The manufacturer NeoCortec www.neocortec.com ordered the studies on antennas in the Sub-GHz range from me in the summer. Since writing technical articles, studies or on the IoT M2M Times takes place in my spare time, such an extensive study takes a little longer. NeoMesh from NeoCortec works like LoRaWAN, Sigfox and Mioty at 868 and 915 MHz. NeoMesh is probably the only mesh net stack in the world that complies with the European duty cycle and also has the router and gateway on battery power. NeoMesh has several other unique features. In the end, NeoMesh, like all others, needs a good antenna. The support requests with antenna problems should become smaller with the study. In order to increase the number of possible readers, I have agreed with NeoCortec that we will include NB-IoT and LTE-M.

Three antenna design notes from Texas Instruments

If you search the internet for PCB antennas for 868 / 915 MHz, you always come up with the three antennas from TI. TI's idea is a good one. Unfortunately, the three layouts are not well documented and some of them are faulty. The first part of the study analyses the three antennas. In the second part of the study, the antennas are broken down into their elements and each part is simulated and explained. In the third part, antennas with functions are assembled from what has been learned. In the fourth part, a few pitfalls are explained. The final part is made up of a few practical examples with real IoT projects, which I am allowed to show and explain. The crowning glory is the simulation of an antenna on the same surface as the L-antenna from TI, which has been copied thousands of times, but with a different structure and significantly better antenna parameters.

Semi-automatic PCB antenna generator

Parallel to the study of antennas for NeoCortec, a semi-automatic antenna generator was developed. The generator currently knows four antenna structures. Just fill in a form, name the mechanical key data for the PCB, the housing and add the requested frequencies. Then you press the pay button, transfer 600 Euros and receive short time later a layout (Gerber files) optimised for your housing and PCB, including return loss, the efficiency of the antenna, Smith Cart, the matching network and much more. The empty PCB can then be ordered and tested yourself or tested and documented by the antenna expert. Or you can transfer the layout to your PCB and fill it with the rest of the components. When the complete PCB is ready, the PCB should be checked again by the expert. If requested, the PCB design can be guided by the designer of the antenna.

Remark: The antenna in the simulation in the picture is the replacement of the TI Helix-L antenna. The antenna has the same installation space as used by TI. We even used the hole in the PCB from TI, thus limiting the installation space. Our antenna does not need a matching network, has no losses in the matching network and has a much better antenna performance. This antenna is one of the four possible antennas of the generator.

The Linux for antennas

Antenna layouts and Linux have one thing in common. Both cost nothing. Everyone can work out his own Linux build or even the antenna. With the study for NeoCortec, everything is explained in detail. You can copy it easily. But it is cheaper if the expert switches on and operates the semi-automatic antenna generator. You can't order and test a PCB and then realise that you have to order the next PCB as quickly as the changes are incorporated into the layout with a mouse click. Enquiries about antennas from 160 MHz to 10 GHz are welcome at harald.naumann (at) lte-modem.com.

The antenna generator can be included on any distributor's homepage. Invoicing is then done by the distributor or by the antenna expert.

Antenna design training in 2022

The training on antennas was announced in a German newsletter before Christmas without an agenda. There will be 8 training sessions of 45 minutes each on antennas, PCB layouts and radio approval for 720 Euro. Only 2 training units per day will be imparted. The training, therefore, lasts 4 days. Questions at the end of the unit will be answered in the video call and by email. The training is held in German and English. If there are enough advance registrations, the training will be held in at least 2 time zones. There are already enough pre-registrations for the training in German. The English training can take place afterwards, on the same day. Depending on the time, listeners from the USA or Australia can also take part. Please send a non-binding pre-registration to harald.naumann (at) lte-modem.com.

IoT antenna designs in practice (e.g. Bluetooth AoD indoor tracking)

In 2022, we will present various antenna designs in very different projects in more detail. All antennas have one thing in common. The tasks cannot be technically solved with standard antennas. If it has to be a 0 USD antenna, it will be difficult with standard antennas. The antenna in the picture is for Bluetooth LE tracking with AoD. The software does not come from the Bluetooth SIG or a chipset manufacturer, but from good old Germany. The antennas also come from good old Germany. The German BLE tracking works and the other one that my business partner bought in France does not work. We can offer 18 to 50 cm positioning accuracy. It is possible to be more precise, but you have to make the antenna arrays bigger. Non-binding enquiries about Bluetooth indoor tracking are welcome.

In 3 days the year, 2021 will be over. I wish you a happy new year 2022, health and success in your wireless IoT projects.

Imprint

• Harald Naumann, Ludwig-Kaufholz-Weg 4, 31535 Neustadt, Germany
• Contact: harald.naumann (at) lte-modem.com, Phone: +49-5032 801 9985, Mobile:+49-152-33877687