Hey all, If I understand correctly, transition frequency is synonymous with the unity-gain bandwidth frequency. With that said, if you divide the gain at the operating frequency by the transition frequency, you should get the operating frequency. Please correct my logic if I am incorrect. The reason why I ask is because I am designing a system that uses HF signals (120 & 125 MHz), and I am in need of a BJT that can handle these sorts of HF signals. At this frequency, I need a current gain, hFE/β somewhere between 5-40 (not exactly sure incoming base current at this time). I'm assuming the gain would need to be somewhere around 5-10. Due to its availability and cost ($0.00), I have researched the 2N2222A NPN BJT. It has a transition frequency of 300 MHz. With my logic above, if I were to operate at 125 MHz, I would receive a current gain close to 2.5, well under what I need for my design. Is my logic correct here? Do I need to look for a BJT with a transition frequency closer to 1 GHz to obtain the required current gain I need? Thank you for your assistance, - Satchmo05 P.S. I apologize for posting this twice, I realized it would be better for me to post this in the EE section, rather than General Engineering Design.