When EE programs cover transistors students are often only taught to bias them with four resistors. However this method of biasing is not able to get the maximum performance from the biased transistor. Better methods of biasing exist, only these methods are often not even shown in EE text books.
In the article that is currently being worked on multiple methods of biasing will be designed. The resulting amplifiers will be simulated and also tested in the real world. The tests and simulations will cover bandwidth, power supply rejection ratio, coupling through the power line and sensitivity to power supply voltage.
To perform these tests a pcb is being designed where it is possible to inject capacitively and inductively interfering signals onto the power supply rail. Also it will be possible to select multiple power supply filters to simulate a filtered analog power supply rail.
The image above shows the current state of the test pcb at the 7th of december 2025. It is important to note that the design of the test pcb is not finished. For the current state of the test pcb and other pcb’s within this project check out the simpleBJTtia github repository.