Tag Archives: Antenna

Doppler Module Teardown Reveals the Weird World of Microwave Electronics

Posted on by

Oscillators with components that aren’t electrically connected to anything? PCB traces that function as passive components based solely on their shape? Slots and holes in the board with specific functions? Welcome to the weird and wonderful world of microwave electronics, brought to you through this teardown and analysis of a Doppler microwave transceiver module.

We’ve always been fascinated by the way conventional electronic rules break down as frequency increases. The Doppler module that [Kerry Wong] chose to pop open, a Microsemi X-band transceiver that goes for about $10 on eBay right now, has vanishingly few components inside. One transistor for …read more

Continue reading Doppler Module Teardown Reveals the Weird World of Microwave Electronics→

OpenEMS Makes Electromagnetic Field Solving… Merely Difficult

Posted on by

To ordinary people electronics is electronics. However, we know that the guy you want wiring your industrial furnace isn’t the guy you want designing a CPU. Neither of those guys are likely to be the ones you want building an instrumentation amplifier. However, one of the darkest arts of the electronic sects is dealing with electromagnetic fields. Not only is it a rare specialty, but it requires a lot of high-powered math. Enter OpenEMS, a free and open electromagnetic field solver.

We would like to tell you that OpenEMS makes doing things like antenna analysis easy. But that’s like saying …read more

Continue reading OpenEMS Makes Electromagnetic Field Solving… Merely Difficult→

Long Range Wireless Internet

Posted on by

While most of you reading this have broadband in your home, there are still vast areas with little access to the Internet. Ham radio operator [emmynet] found himself in just such a situation recently, and needed to get a wireless connection over 1 km from his home. WiFi wouldn’t get the job done, so he turned to a 433 MHz serial link instead. (Alternate link)

[emmynet] used an inexpensive telemetry kit that operates in a frequency that travels long distances much more easily than WiFi can travel. The key here isn’t in the hardware, however, but in the software. He …read more

Continue reading Long Range Wireless Internet→

An Antenna that Really Cooks–Really

Posted on by

[9A4OV] set up a receiver using the HackRF board and an LNA that can receive the NOAA 19 satellite. Of course, a receiver needs an antenna, and he made one using a cooking pot. The antenna isn’t ideal – at least indoors – but it does work. He’s hoping to tweak it to get better reception. You can see videos of the antenna and the resulting reception, below.

The satellite is sending High-Resolution Picture Transmission (HRPT) data which provides a higher image quality than Automatic Picture Transmission (APT). APT is at 137 MHz, but HRPT is at 1698 MHz and …read more

Continue reading An Antenna that Really Cooks–Really→

3D Printed Radiation Patterns

Posted on by

Radiation patterns for antennas can be utterly confusing, especially when presented in two dimensions, as they usually are. Fear not, [Hunter] has your back with 3D printed and color-coded radiation patterns.

In the field of antenna design, radiation patterns denote the relationship between the relative strength of radio waves emitted from antennas and the position of a receiver/transmitter in 3D space. In practice, probes can be used to transmit/receive from documented locations around an antenna while recording signal intensity, allowing researchers and engineers to determine the characteristics of arcane antennas. These measurements are normally expressed as two-dimensional slices of three-dimensional …read more

Continue reading 3D Printed Radiation Patterns→

On Point: The Yagi Antenna

Posted on by

If you happened to look up during a drive down a suburban street in the US anytime during the 60s or 70s, you’ll no doubt have noticed a forest of TV antennas. When over-the-air TV was the only option, people went to great lengths to haul in signals, with antennas of sometimes massive proportions flying over rooftops.

Outdoor antennas all but disappeared over the last third of the 20th century as cable providers became dominant, cast to the curb as unsightly relics of a sad and bygone era of limited choices and poor reception. But now cheapskates cable-cutters like yours …read more

Continue reading On Point: The Yagi Antenna→

A Remotely Tuned Magnetic Loop Antenna

Posted on by

If you are a radio amateur, you may be familiar with the magnetic loop antenna. It’s different from most conventional wire antennas, taking the form of a tuned circuit with a very large single-turn coil and a tuning capacitor. Magnetic loops have the advantage of extreme selectivity and good directionality, but the danger of a high voltage induced across that tuning capacitor and the annoyance of needing to retune every time there is a frequency change.

[Oleg Borisov, RL5D] has a magnetic loop, and soon tired of the constant retuning. His solution is an elegant one, he’s made a remote …read more

Continue reading A Remotely Tuned Magnetic Loop Antenna→

ESP32 WiFi Hits 10km with a Little Help

Posted on by

[Jeija] was playing with some ESP32s and in true hacker fashion, he wondered how far he could pull them apart and still get data flowing. His video answer to that question covers the Friis equation and has a lot of good examples of using the equation, decibels, and even a practical example that covers about 10km. You can see the video below.

Of course, to get that kind of range you need a directional antenna. To avoid violating regulations that control transmit power, he’s using the antenna on the receiving end. That also means he had to hack the ESP32 …read more

Continue reading ESP32 WiFi Hits 10km with a Little Help→

RadiantBee Is A Flying Microwave Antenna Calibration System

Posted on by

Many of the projects we link to here at Hackaday have extensive write-ups, pages of all the detail you could need. Sometimes though we happen upon a project with only a terse description to go on, but whose tech makes it one worth stopping for and unpicking the web of information around it.

Such a project is [F4GKR] and [F5OEO]’s RadiantBee, an attempt to use a beacon transmitter on a multirotor as an antenna calibration platform. (For more pictures, see this Twitter feed.) In this case a multirotor has a GPS and a 10 GHz beacon that emits 250 ms …read more

Continue reading RadiantBee Is A Flying Microwave Antenna Calibration System→

Adding an External Antenna to the Raspberry Pi Zero W

Posted on by

Putting a complete WiFi subsystems on a single-board computer is no mean feat, and on as compact a board as the Zero W, it’s quite an achievement. The antenna is the tricky part, since there’s only so much you can do with copper traces.

The new Raspberry Pi Zero W’s antenna is pretty innovative, but sometimes you need an external antenna to reach out and touch someone. Luckily, adding an external antenna to the Zero W isn’t that tough at all, as [Brian Dorey] shows us. The Pi Zero W’s designers thoughtfully included solder pads for an ultra-miniature surface-mount UHF …read more

Continue reading Adding an External Antenna to the Raspberry Pi Zero W→