Help in receiver front end design_which BPF should I use

[vivek1214]

front-end bpf

hello everyone,
I am designing low IF receiver front end in ADS,I have a confusion that which Band Pass Filter should i use,butterworth ,chebyshev or raised cosine and for 90 degree phase shift should I use phase shifer or time delay component.
Thanks in advance.
vivek

 

[khouly]

receiver + bpf + lna + blick diagram

it will depend , on ur application , and the location of the filter , try to send a block diagram , showing the location of the filter

Khouly

 

[vivek1214]

why bpf infront of lna

hello khouly,
I have attached the block diagram,could you pls see it and suggest me about the filters and phase shifters.

 

[khouly]

frontend bpf

the BPF will depend on ur requirment , sharp response , very flat gain response . so it could be butterworth or cheby

to get very flat gain , use butter worth

about the phase shifter , u can use poly phase circuits

khouly

 

[tyassin]

Hi

I do not now your application.

Maybe you should also consider a bandpass filter before your LNA. I know it will increase you NF, but having a strong interfernce could saturate your LNA and put it well into saturation.

Regards

 

[7rots51]

in front of LNA(between LNA and ANT) we need to use low loss filters,and LC and microstrip filters have high loss ,so we should use other types like as HELICAL filters or CAVITY filter ,... these filters is mechanical and not electronic in construction ,but I can not find any good design information on them,plz send info for us if u have good links,ebook names,Is there any other types of low loss filters?