Isolator and circulator

I heard that isolators and circulators are useful when your circuit is not matched to 50ohm. Someone has information/references about the applications of these devices

yeah , the isolator is very usefully when your circuit is not matched , coz it isolate and prevent the reflected signal from affecting your circuit , it is very useful to use after PA if the antenna is not fully matched , there will be a reflected signal , the isolator prevent this signal from affecting ur PA

khouly

you say it isolates from reflected signals, but anyway the signal is decreased in magnitude due to the unmatch ?

a three port device with in out & iso port terminated.
yes amplitude is decreased but its function is to protect the pa from VSWR damage. reflected power is absorbed in iso port. gooogle for more info.

jay

Hi,

Attach below some datasheet we explanation about isolator!

David

Give me you email an d i will send it to you

It's preferred you post the datasheet here - or even better - point to a link on the Internet. This is an open Forum and others may have interest in your answer.

the aim of the isolator is to protect the sourse from any mismatch, i.e. it allows the source to see a matched load always. this is very usefull in case of vacumm tube devices(magnetrons etc), which will behave irratically in the influence of reflected powere.
and as far as the reduction in signal power is concerned at the load end , due to mismatch, some stub tunning etc may be required to be done, circulator/ isolator wont help.

isolator is a circulator, with one of its ports is terminated.

signal enters the input port and "circulates" in clockwise or counterclock wise direction to output port, if there's no full matched output port, reflected powerl will "circulate" again toward teminated port and it is grounded here.

please refer microwave devices by annapoorna das...

you can learn the aplication of the ferrite devices in this boock:
microwave engineering
Pozar

can u give me design of circulator in hfss