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Follow this example to simulate the "Vout vs. Pin" graph.
ADS cannot directly simulate "Efficiency vs. Pin". To plot this graph, you will need to write a measurement equation to calculate:
n = Vout x Rload / Pin
Although the device model utilized the MESFET library component, the pg 1 of the datasheet mentioned "enhancement PHEMT", not once but thrice. I think the reason behind the choice was that the ADS of that era (early 2000) didn't have a PHEMT component. However, earlier devices from this...
I concur with FvM that the information can be found in the scientific papers of that era, one of which is this: Y. H. Chow, et al, "A 1V, 0.9dB Noise-Figure High Linearity LNA MMIC for Concurrent GPS Handset application".
There are two things that can the increase the output voltage.
1. Match the input impedance. After you have done this, the return loss (at low power) will be <= -10 dB as in AN 1156 fig. 8 and the output voltage vs freq graph will show a peak at your design frequency as in **broken link...
How do you know that the LNA is working? Did you assemble it yourself?
I don't think a DC blocking cap is necessary in your case because the SAW filter at the module input is already blocking DC (please confirm this by measuring the DC resistance between the SAW filter's input & output).
Simulation of your Franklin oscillator shows an open loop gain of ~60 (~8x gain per stage), whereas one-transistor oscillators typically have single digit gain.
Replacing the 470p cap with a variable one can quench oscillation, but most of the control will be concentrated in the 0-5 pF range...
I recommend omitting the RF choke from the simulation because it is intended to be "invisible" at 2 GHz. However, instead of obediently following my recommendation, your interest will be better served by comparing simulations with and without the aforementioned choke. My prediction is that the...
I concur with you that the resistor is a physical component that is added to the circuit. You can find that resistor, although of different values, in all the appnotes associated with ATF-54143 - AN1222, AN1352 (ATF-58 is a relabeled ATF-54) and AN1299. (shameless plug) I am somewhat familiar...
@skatefast08
Correct. The functions of these components are explained in the ATF-54143 appnote: AN1222 pg. 3, (**broken link removed**)
Although one poster speculated "R5=5 Ohm represents the Internal resistance of the Battery", the resistor is actually used to stabilize the ePhemt at very low...
Manufacturers are moving from SC-70, e.g. SOT-323/343 to QFN because the latter is cheaper. The former requires lead-forming, whereas the latter does not. Moreover the former's gull-wing leads are susceptible to bending during automated testing and is a source of over-rejection.
Re: LNA stability question
1&2. see 3
3. The output stability circle will tell you which stabilization option is available, i.e. series or shunt? For example, if the unstable region encloses the Smith chart's short circuit point, then the shunt resistor trick is not available; in this case...
Re: LNA stability question
1. Why did you choose output shunt stabilization (shunt resistor)?
2. Is it the only available stabilization option?
3. Where is the unstable region on the Smith chart?
4. Can shunt stabilization be achieved by connecting R2 in parallel with DC_Feed2? So, with...
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