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i designed a microstrip oscillator with a frequency of 9 GHz.
it was simulated using Ansoft Designer.
A linear model (S2P) was used to represent the transistor, instead of a nonlinear model.
However after I implemented my design in a RT Duroid 5880 board, my circuit oscillated at 10.74 GHz...
I am curious if there is a way to tune a FABRICATED microstrip circuit?
I sent my design (9GHz oscillator) to a fabrication company. After they build its prototype, would I still have a way to tune the prototype?
hey saad770 i saw your reply from my email notifications but i can't find your post here :D
"hay! can i see ur designs because i really need to look them as iim also workiing on it.
and im not able to find the link where u have uploaded ur designs.
kindly please let me know.
thank u so much in...
@biff44
yes sir i designed my oscillator using these conditions that you said.
The impedance from s11 of my active device has a negative real part. The real part of my resonator impedance is negative 1/3 of the input impedance of my active device, so it is positive. [1/3 rule of thumb]
The...
Im designing a microwave oscillator using an S2P file. Because of this linear model, I cannot do any nonlinear analysis, so I'm stucked with the S-parameter output.
How can I know if my oscillator is oscillating?
My adviser told me that if S11>1, my oscillator is now oscillating.
What is the...
Hey I tweak the length and width of the coupling line and achieved a reflection coefficient with a magnitude of 0.39 and a phase of -145.33 degrees. Do you think it is enough to be near that target reflection coefficient? Thanks! :D
sure!
My adviser also told me to change the length of the coupling line. I tried that but at some point, the magnitude also changes, I guess this is a matter of mixing the right dimensions for the ring as well as the length of the coupling line?
Attached here are my designs:
I'm trying to design a simple microstrip ring resonator for my 9 GHz oscillator. My chosen transistor is biased in such a way that it is operating in the potentially unstable region. The substrate I am currently simulating with is RT Duroid 5880 with a dielectric thickness of 3.175mm. I am...
owwww. thank you sir! I was very worried a while ago because of this. thanks sir! I'll be studying the biasing network for my oscillator. GREAT HELP sir :D
Sir I only calculated the K delta from the given S-parameters of the transistor at 9 GHz. I found out that it is unconditionally stable at 9 GHz so I need to do something about it to make it unstable at 9 GHz, which I am not familiar with.
The K delta was computed manually. I did not use any...
I forgot to check the stability of my transistor. Using the K-delta criteria:
K = (1 - |S11|^2 - |S22|^2 + |delta|^2) / 2|S12 * S21| > 1
|delta| = |(S11 * S22) - (S21 * S12)| < 1
for unconditional stability.
When I computed my K and delta, I got K = 1.156 and |delta| = 0.4277 that satisfies...
From my understanding (Please correct me if I'm wrong), radial stubs serves as bypass capacitors in a way that it provides a short circuit. However, this will provide connection between the DC and RF power so there will be a quarter wavelength line that will make this short circuit appear as RF...
I observed that many of you guys use ADS for microwave circuits.
Unfortunately, we don't have ADS here, we only use Ansoft Designer since we have a license for it.
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