RF

Adjustable RF attenuator

RF attenuators are essentially electrical resistor circuits that are put in line with an RF signal and reduce the signal strength. The amount of resistances used is what determines the amount of attenuation. Basic circuits used in attenuators are pi pads (π-type) and T pads. The lost power in the attenuator is converted into heat.

HDMI cable EMC failures

It seems that he quality of video cables sold in EU should be much better than it is now. I am not talking about mechanical strength or ability to transfer signal through, but the electromagnetic compatibility. The Swedish Electrical Safety Agency, together with other authorities within the EU, has tested HDMI and antenna cables. EMC

Antenna isolator teardown

A ground loop in your AV system caused by antenna connection or TV cable is very common if you have your computer connected to the same system. This type of ground loop problem can be solved by using suitable isolator between your AV system and the antenna cable. Antenna isolator is very convient way to

WiFi location

In three years or so, the Wi-Fi specification is scheduled to get an upgrade that will turn wireless devices into sensors capable of gathering data about the people and objects bathed in their signals. In this WiFi is following the footsteps of Bluetooth that got location features already some years ago. “When 802.11bf will be

tinySA RF spectrum analyzer

TinySA is an amazing gizmo! I have already posted some video link on TinySA and here is some mode material on it. RF testing is getting quite popular these days, with many devices featuring wireless capabilities. However, RF test devices are quite expensive, or at least have been, as on few recent years many affordable

Friday Fun: 5G protection shield issues

Buying a 5G protection shield seems to be a zero sum game where you always loose: If you get product that works as advertised you will loose your connectivity and if you buy a non-working you loose your money to a scammer. Conspiracy Theorists Buy Faraday Cages To “Protect” Themselves Then Complain When They Work

50 ohm vs 75 ohm conversion

Coaxial cables are measured by impedance. The most common impedance values are 50 ohms and 75 ohms. different cables. 50 ohms is most often used for radio transmitting and receiving applications. 75 Ohm is primary used for video and audio. 75 Ohm cables are the standard coax cable you find everywhere inside your home and

tinySA cheap pocket size RF spectrum analyzer

A spectrum analyzer measures the magnitude of an input signal versus frequency within the full frequency range of the instrument. The primary use is to measure the power of the spectrum of known and unknown signals. Spectrum analyzers are widely used to measure the frequency response, noise and distortion characteristics of all kinds of radio-frequency

NanoVNA cable measurements

Having a VNA opens up so many possibilities for RF measurements. Typical measurements are antenna matching, RF filters, impedance matching and cable loss. But it an do more. You can use it even to measure the coaxial cable length – a task that is normally performed with time domain reflectometer (TRD), an instrument I have