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M is only real for low frequency coupled inductors where the is negligible time delay for flux changes in the primary to affect the secondary. Any accurate representation of coupled coils (particularly at high frequencies and where they are separated) will show a phase delay to the secondary...
At the risk of doing the OP's homework, this is not true - see the following figure from Lathai "Modern Digital and Analog Communication Systems"
The S/N degradation approaches 0dB as the input S/N becomes very large, but for small (negative) S/N it is unbounded, and becomes much greater...
This is not right. Whilst it is correct in that the synchronous demodulator suppresses the noise in the quadrature channel, which is half the noise, the effect of noise on the envelope detector is much more complex.
The envelope detector is always worse, but rarely by 3dB.
In high S/N...
The fact the structure is open will mean it will radiate. - I don't think this is correct. An open balanced two conductor transmission line has a real characteristic impedance and doesn't radiate, an open microstrip line in homogeneous medium (no dielectric) is TEM and doesn't radiate...
Your...
Two things to watch using the AD979A as an active loop filter:
1. The input bias current is high, of the order of 1uA. This will lead to very high reference spurs unless your loop bandwidth is very low. You can simulate this on ADIsimPLL.
2. The input common mode voltage range makes it very...
That's what I did - showed that if you kept the radiated power constant then the stored reactive power increased as you decrease the substrate thickness.
What is not clear from your analysis is why the ratio of the radiated power to the reactive power drops as you decrease the material...
Consider a half-wavelength microstrip patch antenna at resonance on an electrically thin substrate (thickness a small fraction of a wavelength).
The radiated power is dependent on the voltage at the end of the patch and the patch width and is independent of the substrate thickness. If we hold...
Looking at the simplified schematic, the oscillator is a colpitts using the 10p and 22p capacitors. The 0.5uH - 1.3uH inductor is across the 22p cap, and its purpose is to make the capacitor look inductive at the fundamental frequency you are trying to suppress, as if you replace one of the caps...
How about a monopole and a small loop, this gives you some polarisation diversity all in one plane.
What is the application, without knowing the details of the environment it is hard to know what diversity solutions may assist.
Certainly if either end of the link is hand-held then you almost...
Re: PLL Problem [pls hlp me]
OK then with a 3.2MHz PD freq you should be able to have a 300kHz LBW.
Have you looked at the CP output to see if things are occurring at something like a 3.2MHz rate?
You would expect to see fractional spurs at multiples of 12.3kHz, however depending on...
Re: PLL Problem [pls hlp me]
Go back to basics:
0. check power supplies etc..
1. double check the chip programming, if possible use the test output and send the outputs of the R and N counters there and check the frequency.
2. break the loop before the VCO, use a power supply to drive the...
Re: PLL Problem [pls hlp me]
So just getting the rest of the information from that first design:
1. What is the output frequency, what is the phase detector frequency?
2. I assume it is fractional-N, what is the modulus?
3. is it locked - i.e. is the output frequency correct - have you...
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