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For my 2m power amplifier I still use a tube (3CX1500C7). The output power is in the range of 1.5 kW.
Disadvantage compared to a SS-PA is the high voltage supply (size and weight). Advantage is the robustness against mismatch of the antenna.
As a transmitter manufacturer (former Ampegon) we...
Coupled coils can also be used to "improve" the stopband of a low pass filter.
Here is a (realized) example of a 144 MHz low pass filter (n=7). Two coils are slightly coupled (k<0.1) and thus create an attenuation pole in the stopband.
But it makes sense to test first in the simulation whether...
Here is a fictitious example for illustration: Load impedance: 1 Ω + 2.55 nH
Matching frequency: 500 MHz
Source impedance: 2 Ω / 6 Ω / 20 Ω (selectable within certain limits)
Matching made with a low "pass structure" (n=4). As you can see, there is no well defined passband.
Very important: The constant load impedance only makes sense for one single frequency.
For a matching circuit and/or a filter circuit, the load must be known broadband (or a resistor).
Do you have an equivalent circuit for the load?
Questions about the filter specification : passband? stopband...
Here is an example for clarification:
Known are: Z1 and Z6
The impedance ZZ can be chosen arbitrarily (must have an ohmic component).
Otherwise there are endless possibilities.
Am I getting this right?
Z1 is the load impedance, which will be connected to the right side of B
Z2 is the input impedance of B (right side) and should be conjugate(Z1)
For synthesizing block B this is not enough information! You need the impedance, which is connected on the left side of B.
I dont know the tool "DA_LClowpassMatch" in ADS. But this is a classic textbook example. For only one frequency easy to solve using the Smithchart (graphical method)
With 3 elements in the matching network, you have a degree of freedom. You can choose an element.
In my example, this is the...
Input and output ports must be very weakly coupled to the resonators.
See also examples in the book "Microstrip Filters for RF/Microwave" (Hong/Lancaster).
"Microwave Office" is a very good choice. I am a user of CAD tools since the beginnings of RF simulations (EEsof/Touchstone, Libra, Academy...) until today. The tool is very powerful and still has a reasonable user interface.
For example, you can simulate and optimize in the frequency and time...
Many LC filters have large reflections in the "passband" without the user being aware of this. All phase-optimal filters (e.g. Bessel) have a monotonous increase in reflection in the "passband" (passband is not exactly defined).
The appendix contains a possible LC network with the desired...
Thank you for the simulations! The results are not far from my simulations. If possible and allowed, please save the S-parameter file (Touchstone format xx.s2p), so I will summarize all curves in one plot.
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