Help in receiver front end design_which BPF should I use

EDAboard.com Forum Index -> RF, Microwave, Antennas and Optics -> Help in receiver front end design_which BPF should I use

Author

Message

vivek1214

Joined: 18 Jun 2007
Posts: 105
Helped: 11

08 Oct 2007 21:16 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

Joined: 20 Oct 2003
Posts: 2479
Helped: 343
Location: EGYPT

08 Oct 2007 21:43 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

Joined: 18 Jun 2007
Posts: 105
Helped: 11

08 Oct 2007 23:48 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.

Google
AdSense
Google Adsense

08 Oct 2007 23:48 Ads

Sorry, but you need login in to view this attachment

khouly

Joined: 20 Oct 2003
Posts: 2479
Helped: 343
Location: EGYPT

09 Oct 2007 8:03 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

Joined: 22 Jul 2004
Posts: 340
Helped: 44
Location: Northern Hemisphere

09 Oct 2007 10:53 Re: Help in receiver front end design_which BPF should I use

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

Joined: 17 May 2002
Posts: 1427
Helped: 14

09 Oct 2007 16:22 Re: Help in receiver front end design_which BPF should I use

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?