how to make a limiter withought a pin diode?

[young.microwave.eng]

limiter challenge

dear experts
do you have any idea to make a limiter withought a pin diode?
is it possible to make such a limiter?
i'm waiting for your replies
thanks in advance

 

[kspalla]

limiter challenge

Dear Friend,
Based on the limiting power(dBm), most limiter circuits is actually attenuator with self biased schottkey diode.
You can use a simple diode for limiter operation but it may not work for the desired frequency and the limiting threshold.

 

[young.microwave.eng]

limiter challenge

dear friend
i dont mean you unfourtunatly.how can we use a simple diode instead of pin or schottkey diode?would you please tell me more about your opinion?
thanks for your attention

 

[flatulent]

Re: limiter challenge

One method is to use a differential pair with limited current. When all of the current goes to one side this limits the output voltage.

 

[biff44]

Re: limiter challenge

You did not say what power level, unlimited insertion loss, and frequency. I suspect you are talking about microwave limiters, while some are suggesting video limiters.

 

[flatulent]

Re: limiter challenge

If you are at microwaves, you can run an amplifier beyond the compression point and follow it by a band pass filter to get rid of the harmonics and an attenuator to set the output limiting value.

 

[kspalla]

Re: limiter challenge

how can we use a simple diode instead of pin or schottkey diode?would you please tell me more about your opinion?

young.microwave.eng :You can do it by connecting the two diodes back to back and in shunt with transmission line. Pass an AC signal of 5V 50 Hz, then you will get the limited signal, let say the threshold is 0.65V then the output is limited by this value.
In this application I am not talked about frequency and power but simple diode limiter. Hope you understood.
The circuit is basically a clipper but it is also called as limiter

 

[yendori]

Re: limiter challenge

kspalla,

young.microwave.eng does not want to use diode for his application. hope you understand.

 

[kspalla]

limiter challenge

Ok,
Now I understood that diode can not be used.
limiters are basically non linear devices.
Can I suggest FET than diode?

 

[young.microwave.eng]

limiter challenge

dear friends
thanks to pay attention to my question.let me think about your replies and i'll send you my opinions too.
thanks again

 

[yendori]

Re: limiter challenge

If you choose to use a transistor you will essentially have to use it like a diode in order to create a limiter...I think

 

[young.microwave.eng]

limiter challenge

dear friends
sorry for my incomplete question.i want to have a microwave limiter and it is waveguide type too.I think the best way to have that is FLATULENT opinion.but there is a problem using that.does the amplifier can recieve all powers?
I meant if the power is greater than of what amplifier can recive then what happened?I think the amplifier will be out of order
thanks friends.i will wait for your perfect replies

 

[kspalla]

limiter challenge

Yes yendori, You are right.
If you use the amplifier beyond the limit then it is under severe stress and resulting poor yield.
Is there any concern on the yield?