Rules | Recent posts | topic RSS | Search | Register  | Log in

Diode linearizer

 
Post new topic  Reply to topic    EDAboard.com Forum Index -> RF, Microwave, Antennas and Optics
Author Message
alexandr22061986



Joined: 16 May 2007
Posts: 167
Helped: 7
Location: Ukraine
Post25 Mar 2008 12:02   Diode linearizer
Hi

I want to make a diode linearizer as a part of my PA. I use Microwave Office and have some problem: on the graph input sine wave is distorted, I use bias tee for biasing diods, so DC voltage can't influence on input circle. Have I to match linearizer with input and output 50 Ohm ports?
Have anybody similar projects in MWO?

Thank you.

Last edited by alexandr22061986 on 08 Apr 2008 11:33; edited 1 time in total
Back to top
Manjunatha_hv



Joined: 03 Aug 2005
Posts: 538
Helped: 76
Location: Bangalore-INDIA
Post08 Apr 2008 6:02   Re: Diode linearizer
Hello alexandr22061986,


Yes, you need to match the circuit...
Upload your MWO project file (*.emp) so that we can comment on the same...


---manju---
Back to top
alexandr22061986



Joined: 16 May 2007
Posts: 167
Helped: 7
Location: Ukraine
Post08 Apr 2008 11:32   Re: Diode linearizer
Thank you for help, Manju.

I have uploaded my file. Some problems I have eliminated. For control of nonlinearity level I change bias current of diods. How can I improve, increase control range of intermodulation garmonics level? Maybe I have to add a microstrip lines for phase shifting? And what type of diodes I need to use in MWO? ( PIN, physical model)?

Thank you.

Sorry, but you need login in to view this attachment
Back to top
Manjunatha_hv



Joined: 03 Aug 2005
Posts: 538
Helped: 76
Location: Bangalore-INDIA
Post10 Apr 2008 9:00   Re: Diode linearizer
Hello alexandr,

This looks bit long description, but it is required to know about thw AWRDE environment...
First of all it llooks you have not set the # of Harmonics option to required number...Just for verification once I modified to 9 it shows different spectrum results when compared to default 5 harmonics...so set the required relistic number...

Second I have created new Input power In variable (Pin) to tune the input power level & see how exactly haronics in spectrum plot varies interactively...

see the attached pictures & modified MWO project file for more details...


Third I have created a new copy of the schematic & swept the power for using with VSS for system simulations & added additional input test point to check the input & output spectrum for QPSK modulation source...

Regarding your other queries...
Yes you need to use Microstripline models for actual phase shift or for simulation you can use phase shifter Ideal block...
The Diode models usage in MWO depends on what Vendor device parameters available & corresponding matching/equivalent parameter diode model you need to use in MWO...
for example for detailed accurate parasitic diode model you can use SDIODE (if all parameters available)...

I hope this helps you...

---manju---

Sorry, but you need login in to view this attachment
Back to top
Post new topic  Reply to topic    EDAboard.com Forum Index -> RF, Microwave, Antennas and Optics
Page 1 of 1 All times are GMT + 1 Hour


Abuse
Administrator
Moderators
topic RSS 
sitemap