Thread: Latest RF tutorial uploaded

Hi all,

It's been a while but I've managed to upload another tutorial to

www.rfic.co.uk

This one is satellite communications and is under the systems & devices section...

Differential LNA almost finished - just need to add some equations for linearity.

Bye for now

Ody :o

Ok All,

I've updated and expanded the MOS C-S LNA.

I have now completed and uploaded a Differential MOS LNA Tutorial - that describes Diff LNA design for low noise and linearity calculations.

Bye for now Ody :)

Odyseus,

FYI:

I opened the PIN diode attenuator tutorial. Page 7 of 14 is blank.

Hi All,

I've at last completed the MOS Gilbert Cell Mixer Tutorial and can be found under the RFIC Circuits menu :) Normal web address www.rfic.co.uk..

I'm currently working on a MOS L-C oscillator followed by a Colpitts..

Bye for now

Ody

Hi All,

I've completed another tutorial on basic RF equipment design. This is based on a lecture given by a now retired engineer, i've added some more info plus some ADS examples.

It can be found under the Systems & Devices section.

The L-C oscillator tutorial is nearly done at last!

Cheers

Ody :)

boy your tutorials are amazing. can you have something up for interconnects

odyseus, ur website is great...but can u have some thing about broadband LNA i need it very much.....i search a lot about 5.8 GHz broadband LNA (3 stage) , but do not know how to start?? Pls help....

What a terrific web site, excellent job. The web site is great as it is but if you can include some informations about (PA) module layout that will be superb.

Wonderful job,

Bouchy

hei, wonderful job~

by the way, I would like some material about ring oscillator(900M), where can I find it? 3ks a lot~~

Hi

your site is really great, I use a lot of it in my studies.

Is it possible to put something up on dielectric resonator oscillators? In particular the design of them. I would really appreciate that.

thanks for a very informative site.

I want to know if there is another tutorials starting from relativly low level .. how can i get them ??
thanks alot

Hi all!

At last! - I managed to complete the L-C CMOS VCO (Variable Controlled Oscillator) tutorial - now under the RFIC Circuit menu.

Enjoy!

Cheers

Ody :D

Hi, thanks very much for your tutorial posted! It benefits us too much!
Just want to ask, for the differentail cs LNA,why we have no load for ac-simulation, why a 50ohms terminal is needed for s-parameter simulation? I am confused about this question for a long time! Hope for you answer... Thanks very much

Added after 22 minutes:

Hi, I have another question. Can you show how to design a buffer following the LNA stage? What should be the load of the buffer? Is it 50ohms? Thanks

Originally Posted by spbhu

Hi, thanks very much for your tutorial posted! It benefits us too much!
Just want to ask, for the differentail cs LNA,why we have no load for ac-simulation, why a 50ohms terminal is needed for s-parameter simulation? I am confused about this question for a long time! Hope for you answer... Thanks very much

Most measure equipmet is build for 50 Ohm reference (10 Ohm give very small distace between transmissions line and 900 - 1500 Ohm give very wide distance like High voltage air hanged power line and couple of meters between lines...)



Historic 600 Ohm using for air-hanged phone-line (around 400 mm distance between lines), 300 Ohm using for old TV and FM-broadcast depend of folded loop antenna give this impedances, and dipol give around ~75 Ohm and ground plane-antenna give ~50 Ohm. - and lastest used wide in mobile radio world and measure equipment build for this maket - and setting standard...

50 Ohm is only a reference - you can measure DUT in 50-Ohm NVA for making S-parameters and in simulators recalculate for example 300 Ohm port impedance or complex impedances typical situation on crystal-filters matching - or 2-5 Ohm typical on Power transistors in 1800 MHz etc.

I very fascinate first time long time ago I measure MF-filters separatly, feeding trasistors for this filter net, and complex load after this in separate S-parameter block.. (if not know feeding and load impedances first time - you need measure this as S-parameters)


MF-filters in VNA and 50 Ohm measure impedance seems like skit and crasy unrealistic value (if not know how this working - crystal filter seems possibly broken...).


But in simulator [1] - beginning feeding from S-parametes block transistor (I find working as current generator and high impedances) simulating as port in higher impedance value and filter going from very bad to good and after small adjust complex impedances (around 200-300 Ohm real part and small imaginary part), can make very good filters in simulators - and now understud why people mostly have tunable parallell resonace circurit each end of crystal-filters - just for make tunable very small amount of complex load in range of part of few pF to few nH or so... and very importent factor to give filter good shape.


...and back to phycial equipment now understud why how works and better to repair and tune this.



[1]

I try Vipec!! - open source linear simulator in first moment and working well for this experiment - and checking later on Ansoft for same result (but this is very expensive and need HW-keys/licenses... if using legal version... and give not so much more info compare to Vipec in this case)



/Xxargs

Thanks for you tutorial. Now I have a big problem when simulating the IIP3. How large load you put at the output port side? Just 50ohms ?But isn't the LNA connected to the mixer stage?And the effective load should be much large than 50ohms? (A few kilo-ohms?) Am I right?
How do you simulate IIP3 in ADS?There is a defined function called:ip3_in(), do you use this one to simulate ? The result from my simulation is quite strange, when I sweep the input power, it seems the IIP3 value increase, do you know why? Thanks very much for viewing...

YIG tuned oscillator

hi, I've visite the site, it's wounderful. But there is not something about RF PA, especilly CMOS PA, Now I wonder information about this area.
many thanks!

Hey, would be nice to find something about Helical Array Design, and mechanical design of helices.

Thanks!:D

Hi,

Could you also give an good tutorial on how to exactly set up the phase noise simulation in ADS for accurate pnoise prediction. My VCO is an LC cross coupled type and I found the spectreRF has different result from that of RFDE. It got to be some pnoise simulation setup problem.

Thanks.

please include synthetic apertures and metamaterials also.