On Sep 28, 9:54�am, j <jdc1...@gmail.com> wrote:> On Sep 27, 6:22�am, "cpshah99" <cpshah99@n_o_s_p_a_m.rediffmail.com> > wrote: > > > > > > > >On 09/25/2010 03:17 AM, cpshah99 wrote: > > >> Thanks Tim. > > > >>> If you know the frequency range that you want to receive in, it's much > > >>> better to go > > > >>> Antenna -> �Bandpass -> �AGC -> �ADC -> �etc. > > > >> Just one que: Do we not need anti-aliasing before ADC? > > > >Just one question for you, then: how might a bandpass filter and an > > >anti-alias filter be related? �(hint: > > >http://www.wescottdesign.com/articles/Sampling/sampling.html) > > > >-- > > > >Tim Wescott > > >Wescott Design Services > > >http://www.wescottdesign.com > > > >Do you need to implement control loops in software? > > >"Applied Control Theory for Embedded Systems" was written for you. > > >See details athttp://www.wescottdesign.com/actfes/actfes.html > > > %%%% > > > Thanks Tim for the link, I will have a look at the material. > > > Cheers > > > Chintan- Hide quoted text - > > > - Show quoted text - > > I�ve come to this discussion late, but in skimming through the > messages I didn�t see where the OP specified the analysis bandwidth. > > RF frequency is one issue, and has to do with the radio and > translation of the modulated signal down to baseband. > > But the final analysis bandwidth and required dynamic range determines > stuff just prior to the A/D and the A/D it self. �This of course > assumes that the RF portions, ie, NF and OIP has been designed to > accommodate the desired dynamic range. > > If I�ve missed something, I apologize. > > Regards.- Hide quoted text - > > - Show quoted text -The point I was trying to make earlier is that it seems like you guys are trying to design a radio without enough information ... ultimately giving the OP the wrong path to a successful out come. In general the stuff you're talking about is important but it's much more important to get the spec's right before the pieces start getting assembled and designed. regards
A question on practical receiver
Started by ●September 23, 2010
Reply by ●September 28, 20102010-09-28
Reply by ●September 28, 20102010-09-28
On 09/28/2010 10:01 AM, j wrote:> On Sep 28, 9:54 am, j<jdc1...@gmail.com> wrote: >> On Sep 27, 6:22 am, "cpshah99"<cpshah99@n_o_s_p_a_m.rediffmail.com> >> wrote: >> >> >> >> >> >>>> On 09/25/2010 03:17 AM, cpshah99 wrote: >>>>> Thanks Tim. >> >>>>>> If you know the frequency range that you want to receive in, it's much >>>>>> better to go >> >>>>>> Antenna -> Bandpass -> AGC -> ADC -> etc. >> >>>>> Just one que: Do we not need anti-aliasing before ADC? >> >>>> Just one question for you, then: how might a bandpass filter and an >>>> anti-alias filter be related? (hint: >>>> http://www.wescottdesign.com/articles/Sampling/sampling.html) >> >>>> -- >> >>>> Tim Wescott >>>> Wescott Design Services >>>> http://www.wescottdesign.com >> >>>> Do you need to implement control loops in software? >>>> "Applied Control Theory for Embedded Systems" was written for you. >>>> See details athttp://www.wescottdesign.com/actfes/actfes.html >> >>> %%%% >> >>> Thanks Tim for the link, I will have a look at the material. >> >>> Cheers >> >>> Chintan- Hide quoted text - >> >>> - Show quoted text - >> >> I�ve come to this discussion late, but in skimming through the >> messages I didn�t see where the OP specified the analysis bandwidth. >> >> RF frequency is one issue, and has to do with the radio and >> translation of the modulated signal down to baseband. >> >> But the final analysis bandwidth and required dynamic range determines >> stuff just prior to the A/D and the A/D it self. This of course >> assumes that the RF portions, ie, NF and OIP has been designed to >> accommodate the desired dynamic range. >> >> If I�ve missed something, I apologize. >> >> Regards.- Hide quoted text - >> >> - Show quoted text - > > > The point I was trying to make earlier is that it seems like you guys > are trying to design a radio without enough information ... ultimately > giving the OP the wrong path to a successful out come. > > In general the stuff you're talking about is important but it's much > more important to get the spec's right before the pieces start getting > assembled and designed.Actually we've pointed out several times early on that receiver design is a complex topic and I at least have pointed him to some book-length works. Then we've either answered specific questions or had fun with super-fast ADC specs. But you are correct, and even one book isn't going to cover all there is in receiver design. For that matter, I doubt that there are many individuals out there that have the mathematical, software, and circuits chops to go out and design a complete receiver all by their one-selves. It takes a village to design a receiver. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
Reply by ●September 28, 20102010-09-28
On Sep 28, 12:00�pm, Tim Wescott <t...@seemywebsite.com> wrote:> On 09/28/2010 10:01 AM, j wrote: > > > > > > > On Sep 28, 9:54 am, j<jdc1...@gmail.com> �wrote: > >> On Sep 27, 6:22 am, "cpshah99"<cpshah99@n_o_s_p_a_m.rediffmail.com> > >> wrote: > > >>>> On 09/25/2010 03:17 AM, cpshah99 wrote: > >>>>> Thanks Tim. > > >>>>>> If you know the frequency range that you want to receive in, it's much > >>>>>> better to go > > >>>>>> Antenna -> � �Bandpass -> � �AGC -> � �ADC -> � �etc. > > >>>>> Just one que: Do we not need anti-aliasing before ADC? > > >>>> Just one question for you, then: how might a bandpass filter and an > >>>> anti-alias filter be related? �(hint: > >>>>http://www.wescottdesign.com/articles/Sampling/sampling.html) > > >>>> -- > > >>>> Tim Wescott > >>>> Wescott Design Services > >>>>http://www.wescottdesign.com > > >>>> Do you need to implement control loops in software? > >>>> "Applied Control Theory for Embedded Systems" was written for you. > >>>> See details athttp://www.wescottdesign.com/actfes/actfes.html > > >>> %%%% > > >>> Thanks Tim for the link, I will have a look at the material. > > >>> Cheers > > >>> Chintan- Hide quoted text - > > >>> - Show quoted text - > > >> I�ve come to this discussion late, but in skimming through the > >> messages I didn�t see where the OP specified the analysis bandwidth. > > >> RF frequency is one issue, and has to do with the radio and > >> translation of the modulated signal down to baseband. > > >> But the final analysis bandwidth and required dynamic range determines > >> stuff just prior to the A/D and the A/D it self. �This of course > >> assumes that the RF portions, ie, NF and OIP has been designed to > >> accommodate the desired dynamic range. > > >> If I�ve missed something, I apologize. > > >> Regards.- Hide quoted text - > > >> - Show quoted text - > > > The point I was trying to make earlier is that it seems like you guys > > are trying to design a radio without enough information ... ultimately > > giving the OP the wrong path to a successful out come. > > > In general the stuff you're talking about is important but it's much > > more important to get the spec's right before the pieces start getting > > assembled and designed. > > Actually we've pointed out several times early on that receiver design > is a complex topic and I at least have pointed him to some book-length > works. > > Then we've either answered specific questions or had fun with super-fast > ADC specs. > > But you are correct, and even one book isn't going to cover all there is > in receiver design. �For that matter, I doubt that there are many > individuals out there that have the mathematical, software, and circuits > chops to go out and design a complete receiver all by their one-selves. > � It takes a village to design a receiver. > > -- > > Tim Wescott > Wescott Design Serviceshttp://www.wescottdesign.com > > Do you need to implement control loops in software? > "Applied Control Theory for Embedded Systems" was written for you. > See details athttp://www.wescottdesign.com/actfes/actfes.html- Hide quoted text - > > - Show quoted text -Hmm, again the size of the gang will be spec dependent. But truly, one good system architect and a couple of other knowledgeable souls can get you a long way down the road on some pretty complex designs. Of course seeing it through manufacturing is another deal � �a really big village� is sometimes required depending on the scope of the project. regards
Reply by ●September 28, 20102010-09-28
On 09/28/2010 02:30 PM, j wrote:> On Sep 28, 12:00 pm, Tim Wescott<t...@seemywebsite.com> wrote: >> On 09/28/2010 10:01 AM, j wrote: >> >> >> >> >> >>> On Sep 28, 9:54 am, j<jdc1...@gmail.com> wrote: >>>> On Sep 27, 6:22 am, "cpshah99"<cpshah99@n_o_s_p_a_m.rediffmail.com> >>>> wrote: >> >>>>>> On 09/25/2010 03:17 AM, cpshah99 wrote: >>>>>>> Thanks Tim. >> >>>>>>>> If you know the frequency range that you want to receive in, it's much >>>>>>>> better to go >> >>>>>>>> Antenna -> Bandpass -> AGC -> ADC -> etc. >> >>>>>>> Just one que: Do we not need anti-aliasing before ADC? >> >>>>>> Just one question for you, then: how might a bandpass filter and an >>>>>> anti-alias filter be related? (hint: >>>>>> http://www.wescottdesign.com/articles/Sampling/sampling.html) >> >>>>>> -- >> >>>>>> Tim Wescott >>>>>> Wescott Design Services >>>>>> http://www.wescottdesign.com >> >>>>>> Do you need to implement control loops in software? >>>>>> "Applied Control Theory for Embedded Systems" was written for you. >>>>>> See details athttp://www.wescottdesign.com/actfes/actfes.html >> >>>>> %%%% >> >>>>> Thanks Tim for the link, I will have a look at the material. >> >>>>> Cheers >> >>>>> Chintan- Hide quoted text - >> >>>>> - Show quoted text - >> >>>> I�ve come to this discussion late, but in skimming through the >>>> messages I didn�t see where the OP specified the analysis bandwidth. >> >>>> RF frequency is one issue, and has to do with the radio and >>>> translation of the modulated signal down to baseband. >> >>>> But the final analysis bandwidth and required dynamic range determines >>>> stuff just prior to the A/D and the A/D it self. This of course >>>> assumes that the RF portions, ie, NF and OIP has been designed to >>>> accommodate the desired dynamic range. >> >>>> If I�ve missed something, I apologize. >> >>>> Regards.- Hide quoted text - >> >>>> - Show quoted text - >> >>> The point I was trying to make earlier is that it seems like you guys >>> are trying to design a radio without enough information ... ultimately >>> giving the OP the wrong path to a successful out come. >> >>> In general the stuff you're talking about is important but it's much >>> more important to get the spec's right before the pieces start getting >>> assembled and designed. >> >> Actually we've pointed out several times early on that receiver design >> is a complex topic and I at least have pointed him to some book-length >> works. >> >> Then we've either answered specific questions or had fun with super-fast >> ADC specs. >> >> But you are correct, and even one book isn't going to cover all there is >> in receiver design. For that matter, I doubt that there are many >> individuals out there that have the mathematical, software, and circuits >> chops to go out and design a complete receiver all by their one-selves. >> It takes a village to design a receiver. > > Hmm, again the size of the gang will be spec dependent. > > But truly, one good system architect and a couple of other > knowledgeable souls can get you a long way down the road on some > pretty complex designs.True, particularly when it's a group that's been designing the same type of thing over and over. My point was more that to have just _one_ guy design the _whole_ thing would be pretty phenomenal -- particularly if you look at it from a product perspective, and asked that same guy to do the mechanical package.> Of course seeing it through manufacturing is another deal � �a really > big village� is sometimes required depending on the scope of the > project.Oy. No kidding. -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html
