[Paulo] just tipped us about an Excel based high frequency transistor amplifier calculator he made. We’re guessing that some of our readers already are familiar with these class A amplifiers, commonly used to amplify small audio signals. Skipping over the fact that their efficiency is quite low — they are cheap to make, don’t require many components and usually are a great way to introduce transistors to new electronics enthusiasts. All you usually need to do is a few calculations to properly set your output signals and you’re good to go.
Things are however more complex when you are amplifying 200MHz+ signals, as all the components (complex) impedances have to be taken into account so you can get a nice amplification system. On a side note, at these frequencies your transmission lines impedances may even vary depending on how much solder and flux you left on your SMT pads along the way. [Paulo]’s calculator will therefore compute most of the characteristics of two class A common emitter/collector amplifiers for specified loads.
Awww, HaD already crushed his server. Anyone have a google-cached page?
Probably the open source morons complaining about propriety file formats or something stupid.
I’m an open source moron and the .xlsx file loads perfectly on LibreOffice 4.2.5.2 under Debian Linux, so no need to complain.
Of course, but the complaints come anyway, ’cause, like Microsoft ‘n’ stuff.
In addition to the virtues you mentioned for class-A amplifiers, it should be noted that they are the most linear of the amp classes, and for small-signal use, that is their most important value.
I would like to see the amplifier that is calculated from this fed to LTSpice and get the AC analysis (transfer function plot) for checking the performance.