When your homebrew Yagi antenna only sort-of works, or when your WiFi cantenna seems moody on rainy days, we can assure you: it is not only you. You can stop doubting yourself once and for all after you’ve watched the Tech 101: Antennas webinar by [Dr. Jonathan Chisum].

[Jonathan] breaks it all down in a way that makes you want to rip out your old antenna and start fresh. It goes further than textbook theory; it’s the kind of knowledge defense techs use for real electronic warfare. And since it’s out there in bite-sized chunks, we hackers can easily put it to good use.

The key takeaway is that antenna size matters. Basically, it’s all about wavelength, and [Jonathan] hammers home how tuning antenna dimensions to your target frequency makes or breaks your signal. Whether you’re into omnis (for example, for 360-degree drone control) or laser-focused directional antennas for secret backyard links, this is juicy stuff.

If you’re serious about getting into RF hacking, watch this webinar. Then dig up that Yagi build, and be sure to send us your best antenna hacks.

In a recent video, [Shahriar] from The Signal Path has unveiled the intricate design and architecture of optical HDMI cables, offering a cost-effective solution to extend HDMI 2.0 connections beyond the limitations of traditional copper links. This exploration is particularly captivating for those passionate about innovative hardware hacks and signal transmission technologies.

[Shahriar] begins by dissecting the fundamentals of HDMI high-speed data transmission, focusing on the Transition Minimized Differential Signaling (TMDS) standard. He then transitions to the challenges of converting from twisted-pair copper to optical lanes, emphasizing the pivotal roles of Vertical-Cavity Surface-Emitting Lasers (VCSELs) and PIN photodiodes. These components are essential for transforming electrical signals into optical ones and vice versa, enabling data transmission over greater distances without significant signal degradation.

A standout aspect of this teardown is the detailed examination of the optical modules, highlighting the use of free-space optics and optical confinement techniques with lasers and detectors. [Shahriar] captures the eye diagram of the received high-speed lane and confirms the VCSELs’ optical wavelength at 850 nm. Additionally, he provides a microscopic inspection of the TX and RX chips, revealing the intricate VCSEL and photodetector arrays. His thorough analysis offers invaluable insights into the electronic architecture of optical HDMI cables, shedding light on the complexities of signal integrity and the innovative solutions employed to overcome them.

For enthusiasts eager to take a deeper look into the nuances of optical HDMI technology, [Shahriar]’s comprehensive teardown serves as an excellent resource. It not only gives an insight in the components and design choices involved, but also inspires further exploration into enhancing data transmission methods.