laplace2000
Electrical
Many Microwave textbooks told me that during the process of oscillation, initially, it is necessary for the overall circuit to be unstable at a certain frequency, that is the loop resistance should be negtive.
but I find this theory incorrect, when I try these values:
Zload=75+j*30; (load impedence)
Zin=-100-30*j; (impedence looking into the negtive resistance device)
Z0=50; (characteristic impedence)
I found
Rloop=-100+70=-30<0 but
abs(GamaLoad*GamaIn)=abs(((Zload-Z0)/(Zload+Z0))*((Zin-Z0)/(Zin+Z0)))=0.8 <1, so it is still stable!
what is wrong? is the theory wrong, or am I wrong?
Who can help me? Thanks!
but I find this theory incorrect, when I try these values:
Zload=75+j*30; (load impedence)
Zin=-100-30*j; (impedence looking into the negtive resistance device)
Z0=50; (characteristic impedence)
I found
Rloop=-100+70=-30<0 but
abs(GamaLoad*GamaIn)=abs(((Zload-Z0)/(Zload+Z0))*((Zin-Z0)/(Zin+Z0)))=0.8 <1, so it is still stable!
what is wrong? is the theory wrong, or am I wrong?
Who can help me? Thanks!