Looking for structure which extract IF in mixer

hello,

instead of LPF, there is structure based on radial stub with two lines but till know i did not find the dimensions...... is someone has an idea ?

Look at Steve Maas' Mixer Book.

The radial stub is a broadband short @ LO, RF frequency.

The transmission lines are inductive to block the RF,LO and pass the IF.

So of course it is basically an LPF

thank you yendori,
I tried to see in :
1. Microwave Mixers(Artech)(1992) - MAAS
2. The Rf And Microwave Circuit Design Cookbook (Maas, 1998 Artech H)

but i did not find the uses radial stub with transmission line as LPF to suppress suprious in the mixer....

how can we relize that structure, i.e, what about the dimension, is the radial stub is quater wavelength ? and for transmission line ?

Added after 2 hours 10 minutes:

I tried to make radial stub placed between 2 microstrip lines, i could not get the LPF response with that structure even i have used tune...

is someone have an idea about that ?

Many thanks in adavance

N

i want to supress all spurious overs 24 Ghz.....

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