gps front end design
but i find gps receiver chip has usually two bits output sampling data, I wish to be able to find a chip whose IF(immediate frequency) is analoy output, thus i can obtain the data i want through ADC.
can you give me some advice?
Hi,
Maxim has an RF that gives you analog output. If you are not working on the HP-GPS I suggest you avoid any analog output receiver. IT IS A PAIN IF YOU DO NOT GET PROPER COMPONENTS OR BOARD.
Hope this helps,
brm
HI, brmadhukar
can you tell me the chip type? I need it very much!
I want to try it, though I think your advice is very pertinent. hope your helps!
Hi!
i am looking maxim RF-IC chips as well.
I know they develop 4 types
MAX2740,2741,2742,2745,
But it takes time to get since they are not quite common.
Please tell us if you can find it, thanks
You may also find the NEC 1007k, 1008k and 1009k GPS RF IC, too.
Yes, I have heard about that NEC series, they are SiGe Process,
Maxim is RFCMOS. :)
Hi,
From my experience,
Maxim was a pain designing with and the support was stopped after some time. (there was some revamping in MAXIM, but whatever the support I got it was excellent). You need to follow the exact recommended layout there was intefreernce of the refrence clock and required design of some odd filters. BUT IT WORKED.
Now I have stopped working on the RF side for time being. However I have heard that NEC is also quite difficult to work with.
B R M
Thanks for your reply.
I know SONY's GPS does not contain AGC, but it is 1-bit ADC.
Speaking of AGC, which do you think better? AGC/PGA or limit amplifier?
thank you!
Hi,
Limiters are not really useful except in case where a voltage surge is expected and in this case u need to use a limiter (at discrete level). For IC level I am not aware what is the cutoff they can provide.
I would still prefer AGC, for normal operation. How to do it in an analog front end is a bit difficult.
HOPE THIS HELPS.
Madhukar B R