Simo.Da
Junior Member level 2
Hi everyone,
I am a student at Sheffield University and I don't have a solid experience in the RF design.
I am working on a project trying to design a class A amplifier using BPF740F BJT transistor at 1GHz to show how the output voltage swings between 1V and twice the V_DC and current also swings between 0mA and twice I_Cmax for the selected transistor within the linear region, then I am going to drive the base of the transistor a bit harder to switch from class A to class C (no longer work in linear mode).
What I have done are: I have calculated the R_opt (112 Ohms) depending on load line method and figured out the V_DC(5.5 V), then I did a matching for the input, but still getting wrong output.
Once I am increasing the biasing on the base, the Ic exceeds twice the maximum collector current (which is 40 mA), and the collector-emitter voltage decreases to be less than twice the DC (11 V).
I am struggling to figure out how to solve this problem, or what should modify of consider in order to solve this issue?
Please find attached a screenshot of my schematic I have done using ADS
If you require further information please let me know.
Your help is much appreciated!
I am a student at Sheffield University and I don't have a solid experience in the RF design.
I am working on a project trying to design a class A amplifier using BPF740F BJT transistor at 1GHz to show how the output voltage swings between 1V and twice the V_DC and current also swings between 0mA and twice I_Cmax for the selected transistor within the linear region, then I am going to drive the base of the transistor a bit harder to switch from class A to class C (no longer work in linear mode).
What I have done are: I have calculated the R_opt (112 Ohms) depending on load line method and figured out the V_DC(5.5 V), then I did a matching for the input, but still getting wrong output.
Once I am increasing the biasing on the base, the Ic exceeds twice the maximum collector current (which is 40 mA), and the collector-emitter voltage decreases to be less than twice the DC (11 V).
I am struggling to figure out how to solve this problem, or what should modify of consider in order to solve this issue?
Please find attached a screenshot of my schematic I have done using ADS
If you require further information please let me know.
Your help is much appreciated!