Category Archives: antenna

Raspberry Pi W Antenna Analysis Reveals Clever Design

The old maxim is that if you pay peanuts, you get a monkey. That’s no longer true, though: devices like the Raspberry Pi W have shown that a $10 device can be remarkably powerful if it is well designed. You might not appreciate how clever this design is sometimes, but this great analysis of the antenna of the Pi W by [Carl Turner, Senior RF Engineer at Laird Technology] might help remind you.

[Carl] used some fancy toys in his analysis, such as the awesome-looking antenna test chamber that his employer uses to test designs. He used this to measure …read more

Continue reading

Posted in 2.4 ghz, antenna, Antenna Design, Raspberry Pi, Raspberry Pi W, teardown, wifi, wireless, wireless hacks | Leave a comment

3D Printed Antenna is Broadband

Antennas are a tricky thing, most of them have a fairly narrow range of frequencies where they work well. But there are a few designs that can be very broadband, such as the discone antenna. If you haven’t seen one before, the antenna looks like — well — a disk and a cone. There are lots of ways to make one, but [mkarliner] used a 3D printer and some aluminum tape to create one and was nice enough to share the plans with the Internet.

As built, the antenna works from 400 MHz and up, so it can cover some …read more

Continue reading

Posted in 3d printed antenna, 3d Printer hacks, antenna, discone, radio hacks | Leave a comment

Harvesting Energy from the Earth with Quantum Tunneling

More energy hits the earth in sunlight every day than humanity could use in about 16,000 years or so, but that hasn’t stopped us from trying to tap into other sources of energy too. One source that shows promise is geothermal, but these methods have been hindered by large startup costs and other engineering challenges. A new way to tap into this energy source has been found however, which relies on capturing the infrared radiation that the Earth continuously gives off rather than digging large holes and using heat exchangers.

This energy is the thermal radiation that virtually everything gives …read more

Continue reading

Posted in antenna, diode, electronics, energy, green hacks, harvesting, infrared, quantum, radiation, tunneling | Leave a comment

Tapping into a Ham Radio’s Potential with SDRPlay

Software-defined radios are great tools for the amateur radio operator, allowing visualization of large swaths of spectrum and letting hams quickly home in on faint signals with the click of a mouse. High-end ham radios often have this function built in, but by tapping into the RF stage of a transceiver with an SDR, even budget-conscious hams can enjoy high-end features.

With both a rugged and reliable Yaesu FT-450D and the versatile SDRPlay in his shack, UK ham [Dave (G7IYK)] looked for the best way to link the two devices. Using two separate antennas was possible but inelegant, and switching …read more

Continue reading

Posted in amateur, antenna, FT-450D, ham, Omni-Rig, radio hacks, RF, sdr, sdrplay, spectrum, waterfall, yaesu | Leave a comment

Start Tracking Satellites with This Low-Cost Azimuth-Elevation Positioner

Tracking satellites and the ISS is pretty easy. All you really need is an SDR dongle or a handheld transceiver, a simple homebrew antenna, and a clear view of the sky. Point the antenna at the passing satellite and you’re ready to listen, or if you’re a licensed amateur, talk. But the tedious bit is the pointing. Standing in a field or on top of a tall building waving an antenna around gets tiring, and unless you’re looking for a good arm workout, limits the size of your antenna. Which is where this two-axis antenna positioner could come in handy. …read more

Continue reading

Posted in antenna, azimuth, elevation, iss, positioner, radio hacks, rotator, satellite, stepper | Leave a comment

Snazzy Balun Lets Ham Use Off-The-Shelf Coax

It’s a dilemma many hams face: it’s easy to find yourself with a big spool of RG-11 coax cable, usually after a big cable TV wiring project. It can be tempting to use it in antenna projects, but the characteristic impedance of RG-11 is 75 Ω, whereas the ham world is geared to 50 Ω. Not willing to waste a bounty of free coax, one ham built a custom 1:1 current balun for a 75 Ω dipole.

Converting between balanced and unbalanced signals is the job of a balun, and it’s where the device derives its name. For hams, baluns …read more

Continue reading

Posted in 1:1, amateur, antenna, balanced, balun, bifilar, dipole, Guanella, ham, radio hacks, unbalanced | Leave a comment

FM Snake Feeds Off Radio Waves

[Eric Brasseur] built a radio-detecting snake that consists of a LED that lights up when around reasonably strong radio waves. Near an FM radio mast you’ll find a huge amount of waste energy being dumped out in the 88 to 108 MHz range.

[Eric]’s rig consists of a pair of 1N6263 Schottky diodes, flip-flopped with one set of ends soldered to the antenna and the other ends soldered to the leads of the LED with about a foot of wire in between. The antenna can be a single wire as the diodes are soldered together. This one is around 4 …read more

Continue reading

Posted in antenna, fm radio, led, news, schottky diode | Leave a comment

Piezomagnetic Trick Shrinks 2.5 GHz Antennas

To a ham radio operator used to “short”-wave antennas with lengths listed in tens of meters, the tiny antennas used in the gigahertz bands barely even register. But if your goal is making radio electronics that’s small enough to swallow, an antenna of a few centimeters is too big. Physics determines plausible antenna sizes, and there’s no way around that, but a large group of researchers and engineers have found a way of side-stepping the problem: resonating a nano-antenna acoustically instead of electromagnetically.

Normal antennas are tuned to some extent to the frequency that you want to pick up. Since …read more

Continue reading

Posted in antenna, MEMS, physics, piezoelectric, radio, wireless, wireless hacks | Leave a comment

Antenna Basics by Whiteboard

Like a lot of people, [Bruce] likes radio controlled (RC) vehicles. In fact, many people get started in electronics motivated by their interest in RC. Maybe that’s why [Bruce] did a video about antenna basics where he spends a little more than a half hour discussing antennas. You can see the video below.

[Bruce] avoids any complex math and focuses more on intuition about antennas, which we like. Why does it matter that antennas are cut to a certain length? [Bruce] explains it using a swing and a grandfather clock as an analogy. Why do some antennas have gain? Why …read more

Continue reading

Posted in antenna, antennas, radio hacks | Leave a comment

Doppler Module Teardown Reveals the Weird World of Microwave Electronics

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

Posted in antenna, Doppler, local oscillator, microwave, mixer, radar, radio, radio hacks, resonator, RF, teardown | Leave a comment