Power amplifier bias designCHAPTER 11 Power Amplifier Bias Circuit Design 11.1 Introduction The oscillatory habits of RF power transistors are an infamous aspect of RF power amplifier design. This much-dreaded skeleton jumps out of its closet at the most inconvenient times, frequently causing destruction and panic in its wake. Its effects are most prevalent at lower frequencies in the MHz to VHF range, where the terminating impedances of an RF power device are mainly defined by the bias insertion networks. The design of bias networks for any RF power amplifier therefore plays an important part in establishing stable operation. The subject has a curious history, which takes us into the murky waters of cultural divides―not just the different world-views of low frequency analog and microwave designers, but also the ov……