Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.
How can an open loop RF active circuit have a positive S11? As the Keysight ADS oscillator design guide says you need to make sure the S11 is on the RHP or encircling the 1+j0 point. What causes this to happen? If I want to create my own oscillator from a transistor, how would you pick the...
Then can you explain why many papers and Google say that you need at least a 180 degree phase shift to create an oscillator? Not 0 or 360 degrees. See example paper here on page 4: Design and Simulation of RF CMOS Oscillators in Advanced Design System ...
Don't oscillator work when phase shift is 180 degrees or 0 degree? Because in the oscillator design guide on the keysight webpage as shown in a screenshot below, says the widespread belief is when the phase of the transfer function is 0 and magnitude greater than 1 then the system is unstable...
Hi BigBoss, I actually used an RFC this time, used an emitter resistor to lower my amps to get 20 mA and used a 3VDC power supply. I actually get no harmonics now, since I used an RFC. I dont understand why I get a transient with about 9 GHz and I used a 9GHz fundamental frequency, but no...
I actually got it to work. I guess the reason was that I put in the wrong fundamental frequency in for the harmonic balance. I put in 1 GHz, when its supposed to be around 4 and 5 GHz. Below is the 1 GHz harmonic balance simulation and the 2nd picture is the 5 GHz harmonic balance. I also don't...
What could I possibly be doing wrong with my harmonic simulation in ADS, when my transient has an oscillation between -500 mV to 500 mV. Shouldn't I get a harmonic magnitude at the frequency of the oscillation?
what could I possibly be doing wrong with this circuit? I have the correct Vce ~ 2V and Ic ~ 20 mA and I have the blocking capacitors to keep DC from interfering with the terminations. Shouldn't I get the same result for maximum available gain at the same frequencies shown on the datasheet? Thanks
what if I was trying to design a ring oscillator and you had 3 transistor, each output would need a 60 degree phase shift to become 180 in order to feed back to the input to create an oscillator. my minimum phase shift for this transistor is a no less than 87 degrees or so as shown on the graph...
Shouldn't the phase change of this CS amplifier be 180 degrees? If so, then why does my AC phase simulation show every frequency being less than 180 degrees? See details in images. Thanks
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
