Ultra-wideband filter design (need help)

[kpcheah]

Hi all,

i am required to design an microscrip ultra-wideband filter with fractional bandwidth of 110%, center frequency of 6.85 GHz (3.1GHz to 10.7GHz). What is the best way to design it? Pls give me some suggestion, and do post me related paper and e-book.

I need help urgently.

Specification:
fractional bandwidth: 110%
center frequency: 6.85GHz
insertion loss: <0.1dB
return loss: >10 dB

Thanks.

 

[kspalla]

You can use cascaded sections of high pass and low pass circuit.

 

[Phytech]

With this wide bandwidth, HP+LP is the best choice.

 

[kpcheah]

is there any other method beside cascade highpass and lowpass?

 

[Aya2002]

see this title

also see

 

[burton]

you can use MMR in which the higher mode in SIR can be used for a transmission pole in the passband and use strong I/O coupling. Or you can use quasi-lump filter, but I am not sure if the insertion loss can be 0.1 dB.