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Filter Specification in CDMA IS95 (Read 3550 times)

chingkailun

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Malaysia

Filter Specification in CDMA IS95
Dec 25^th, 2004, 7:35am

Hi all,

I am doing bandpass filter for wireless receiver front end(IF conversion architecture). The filter is IF filter which is situated right after the mixer.

Is there any standard specification for the filter(CDMA IS95 standard)?
I know the standard bandwidth of the filter in CDMA is 1.25MHz.
If anyone knows the standard such as
1. centre frequency,
2. gain,
3. input equivalent noise/noise figure,
4. linearity(IP3/compression point),
5. attenuation, and others relevant info, plz let me know.

Thanks!I really need your help...

Kailun

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DaveB

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Re: Filter Specification in CDMA IS95
Reply #1 - Jan 11^th, 2005, 8:16pm

I'm not sure that I'm reading your request correctly, but here it goes. Bandpass filters for RF are generally passive, crystal or SAW based devices.

1) The center frequency is your IF Frequency
2) Gain (Loss Actually) is as small as possible.
3) Noise figure is the inverse of the gain
4) Linearity generally isn't a concern for filters.
5) Those are really the big ones. You might want to think about spurious rejection and ultimate attenuation floors as well, but that is left as an exercise for the student :)

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boa Junior Member Offline Posts: 31	Re: Filter Specification in CDMA IS95 Reply #2 - Jan 11^th, 2005, 9:09pm I think that the answers to you questions are not in the CDMA standart, but depend on the frequency planning of your receiver.
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DaveB Junior Member Offline Posts: 15	Re: Filter Specification in CDMA IS95 Reply #3 - Jan 15^th, 2005, 11:47am Boa: you are right, most of these fall into fairly generic Front end design. Dave
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