Help on Mixer isolation - isolation ports for a mixer

[nassim1]

mixer isolation

Dear colleagues,

1. I want to know how can we determine isolation ports for a passive or active mixer ??

is there related to S parametres ?? or related to the Powers such as P_LO, P_RF and P_Output ??


2. For passive mixer, typical conversion loss is about -6 dB but most of published papers show that conversion loss is positive (which is in reality for active mixers) value and geater than 10 dB, for this point, really i do not understand why? can someone clarify this point ??


many thanks in advance,

N

 

[kspalla]

passive mixer 6 db loss

is there related to S parametres ?? or related to the Powers such as P_LO, P_RF and P_Output ??

S-para is also based on powers( incident and reflected)

For passive mixer, typical conversion loss is about -6 dB but most of published papers show that conversion loss is positive (which is in reality for active mixers) value and geater than 10 dB, for this point, really i do not understand why? can someone clarify this point ??

May I ask you to share the paper having convection gain for passive mixer?

 

[nassim1]

mixer isolation

Thank you kspalla,

i have understoud the isolation ports means to calculate the different S-parameters such as: S21, S23 & S31 for RF-LO, RL-IF and LO-IF respectively ??

i attached file some papers talk about conversion loss with passe device...

 

[kspalla]

Re: Help on Mixer isolation

In mixer,
6 measurements excluding return loss.
LO-RF and LO-IF is called leakage
RL-IF is called conversion loss/gain.
IF-RF is called Isolation.

RF-LO and IF-LO are not important as LO power is much stronger.

Passive mixers with conversion loss is 6dB is a good one but it may suffering from Isolation which is important.

All the attachments talk about conversion loss.
Can i again ask for

May I ask you to share the paper having convection gain for passive mixer?

 

[nassim1]

Re: Help on Mixer isolation

As i have written, conversion loss normally neagtive value which is typically -6 dB and the paper that i sent they talk avout conversion loss but with positive value!!!

For that, i have wriiten conversion gain in passive mixer... i do no have paper which talk on conversion gain for passive mixer.

you can take remark on the papers that i sent, i.e, if conversion loss is positive that 's mean that we have conversion gain......

i hope that you have understood me..

many thanks for explanation

 

[wireless man]

Help on Mixer isolation

For passive mixer, the 6 dB conversion loss is reasonable, in another word, the conversion gain is -6 dB. My opinion only!

 

[kspalla]

Help on Mixer isolation

Wireless man is correct.
conversion loss 6 dB is nothing but conversion gain of -6 dB.

 

[sanredrose]

Re: Help on Mixer isolation

I also agree with Wireless man. Conversion Loss 0f 6 dB means its conversion gain of -6 dB.

If you have time take a look into the datasheet published by Hititte Microwave Corporation. If you look into their Active Mixer Data Sheet, you will find their specfications as Conversion Loss = 6 dB, which means its a loss of 6 dB.

 

[nassim1]

Re: Help on Mixer isolation

Many thakns for explanation........