Recent content by kent

Hi guys I am now building a simple synchronous detection circuit, I have now two signal generators, one generate a 20 MHz sinusoidal signal, and the other one gives a 19.99 MHz signal. If now I want to down-convert the 20 MHz signal into a 10 kHz signal, what kind of mixer (part number) can I...

Sorry guys...wrong link... Here is the correct one: http://www.analog.com/en/prod/0,,770_843_AD9854,00.html

Hi Guys.. I am try building a circuit which involves with a AD9854 DDS(Direct Digital Synthesis) chip to generate a frequency controlable sine wave for me... The problem for me is that the Master clock supply for the chip need to be around 200MHz...I don't know whether there is any crystal...

Hi guys I want to build a I/Q demodulation circuit...operate at 20MHz...does anyone have any experience on building this circuit in a similar frequency range? what kind of opamp + mixer shall I go for? There are too many parts I don't even know where to start from... I hav browsed through...

Thanks you!...The size of my coil is quite small...so the inductance of my coil is around 10uH...which is OK...I think...

Driving a coil...Voltage drive..? Current drive..? Hi Guys As the title...I am now having a 10 turns coil, does it really matter that I drive it with sinusoidal voltage signal or a sinusoidal current signal? Will it affect the response of the coil? (like resonance frequency, Q factor...etc)...

Thanks Berkeman! I wil try it now! I actually just come out with an idea...if I use a thin co-axial cable to wind a coil (since my coil is only 5 turns, the size shouldn't be a problem..) Do you think that wil make a good electric screening as well? of course the outer shield of co-axal cable...

Quote from Berkeman: ( So for example, you can make a ring of metal foil that is the same diameter as your coils but wider (in the polar direction) so that it is a good shield, with a hole in the middle and a narrow cut out of the side to make like a "C" shape. Minimize the width of the cut-out...

Hi All I would like to build a synchronous detection circuit for detecting the real and imaginary part of the signal (I and Q value), the operating frequency for the system is 20 MHz...I would like to know is there any existing chip that can generate the quadrature signal for me (cos wave and...

Thanks guys.. Yes...I have tried both QuickField and MagNet...but the bad things about student version is that there is always a node limitation...and doesn't have AC analysis function...i am downloading Microcap9 Demo and see whether it will be better! Actually the aim of my experiment is to...

Thanks for all your guys help... Does anyone know whether there is any good EM field simulation software that can simulate this kind of experiment? (preferbly freeware...but commercial package is also fine...)? All I want to do is to compare my observation with the theorectical result... Kent

Thank you, berkeman and waht: Yes, I am using one channel of the 'scope to monitor the drive coil (as the reference), and the other to monitor the pickup coil? about the electrostatic screening...it should be placed in between the coils right? to prevent the coupling...do you think a...

Hello All, I did a simple mutual inductance experiment recently which involving two coils (5 turns each) in series with a high frequency signal (MHz range) running through them. One coil is directly connected to function generator via a co-axial cable, and the other coil is connected to...