The self-resonance of a capacitor imposes the frequency limit where it acts as a true capacitive reactance to the circuit. After the resonance point, the impedance rotates and the capacitor starts to act inductive. This frequency limit can be measured using a network analyzer and a simple JIG. I used
In the vacuum tube era and in the early days of transistors, engineers struggled to achieve the highest performance from each amplifier stage. This was done because cost of active devices were prohibitive. When dealing with common emitter stages, the frequency roll-off is primarily dominated by the feedback capacitance. Any
This test project started as a study of the work from Matjaz Vidmar, published at the Microwave Journal in 1999, the original publication can be read here. As stated by Matjaz, today's frequency division is largely done by digital semiconductor logic. Even so, analog regenerative dividers can be
In this article we are going to discuss and prototype an old technique used for high frequency synthesis, that for many years was the only way to approach tens of gigahertz. PIN diodes have a large signal behavior, very similar to step-recovery diodes. Even with SRD becoming expensive and hard
Oscillation at an overtone frequency allows a crystal oscillator to run at an odd multiple of the main crystal frequency (3f, 5f, 7f). This is a simple way to frequency multiplication in crystal oscillators. Odd modes of operation are possible because of the mechanical construction of common AT crystals. From