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300kHz spurs on the LO is definitely coming from the LO PLL. You will probably have to live with them.
I don't know the specs on your Spectrum analyzer but it might actually be with in the specified limitations of the instrument, they are nearly 60dB down from the carrier and at 20GHz this might...
In post #2 I was referring to the two chokes on the output side.
The input L is critical and can not be a choke. It has to be hand wound to get a high Q inductor.
The best would be to use the same wire diameter as the designer so as to be sure to get the correct inductance and Q.
But if you...
The input LC components and values are vital as they match the 50 ohm input impedance to the impedance of the transistor stage.
Get it wrong and you can easily loose 20 or 30 dB of gain, e.g. you will have a fine attenuator instead of an amplifier :-).
The output L is less critical and can be a...
You can not do both at the same time.
But you can build antennas were you can switch between linear and circular polarization, best example is a crossed dipole.
A circular polarized antenna will receive a linear polarized signal fine but with a 3dB loss, same the other way around.
Should be absolutely fine.
Depending on the modulation rate you would use, you could end up with quite a wide band signal and thus take up a lot of bandwidth in the radio band you intend to use it on but other than that - no problem.
No, it would be perfectly fine.
LNA are usually designed for low noise, but some of them are also designed for high IP3 or high dynamic range so they can be great low level PAs.
Go for it!
Well it's like we have a income and expenses.
It's just makes sense to have the two instead of seeing expenses like "negative income".
Expenses have a negative sign built in just like loss has.
That way we can say the feed-line has a loss of 12dB instead of saying it has a negative gain of...
First lets start with what Q really is about.
The Q factor is the amount of energy stored - in a component or resonant circuit - compared to the amount of energy dissipated as heat.
The energy is stored as a magnetic field in an inductor and as an electric field in a capacitor.
In a resonant...
No that wont change anything.
Say you have two crystals one at 10MHz and one at 11MHz. They have a stability of 1ppm so they drift to 10.000 010MHz and 11.000 011MHz.
Mix them to their sum and you get 21.000 021 MHz with is the same stability - 1ppm.
Mix them to their difference and you get...
a 6dB pad is another way of saying the the oscillator goes in to a attenuator that attenuates the signal by 6dB.
To add attenuators between different RF stages is a classic way of isolating them so they can't influence each other, in this case so that the load the oscillator sees wont affect...
You mean they are longer, right?
They should be be the same width regardless of freqency if you compare it to other designs using the same board thickness and material.
It's hard to understand directly why you see higher loss in your UHF design compared to your L band designs.
It should be as...
The 33ohm resistor only very marginally affects the collector current. Its the feed back resistors that controls it.
The 33ohm resistor is a low pass filter with the 1nF C and the 100uH L.
This low pass filter provides stability to the circuit to avoid oscillation, the value is most likely not...
I haven't gone over your calculation so I will not comment on them but I would like to point out that the signal to noise ration for a modulated signal can be very much lower than the decoded signal to noise ration.
So in many cases you only need your signal to be a few dB over the noise floor...
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