Re: [USRP-users] B200 Noise Figure Meter

[Derek Kozel via USRP-users]

Hi Dan,

The E310/E312 has the switchable set of receive and transmit filters which
the B2xx does not. This will impact the noise figure due to the additional
losses of the switches and filters. As with most receivers an external LNA
and filter matched to a frequency of interest will reduce the total system
noise figure.

Derek

On Sun, Feb 4, 2018 at 5:55 PM, Dan CaJacob via USRP-users <
usrp-users@lists.ettus.com> wrote:

> Yep, I am aware of that document and I am using the Y-factor method.
>
> The 3 dB attenuator was calibrated with the B200 - i.e. I measured the NF
> of the USRP + 3dB attenuator as a system. That data then serves as the
> calibration data to correct for it's contribution to the subsequent NF
> measurement of the B200 + 3dB pad + DUT.
>
> I saw the same poor performance below 1 GHz when using the 3dB pad.
>
> On Sun, Feb 4, 2018 at 11:44 AM David Bengtson 
> wrote:
>
>> A 3dB attenuation will really improve the reflection coefficient.
>> Using this calculator
>> http://www.rfcafe.com/references/calculators/vswr-return-loss-conversion-
>> calculator.htm
>> you can see that a 3 dB attenuation will improve a 3:1 VSWR to 1.7:2,
>> or a 6 dB return loss to 12 dB, so you've really improved the match.
>> The gory details of noise figure and match are in here
>> http://literature.cdn.keysight.com/litweb/pdf/5952-3706E.pdf and
>> Keysight has a spreadsheet to do the calculations here
>> https://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&;
>> ckey=96887&nid=-34815.0.00&id=96887
>> (Probably more detail than needed)
>>
>> Did you add the 3dB attenuator to the noise figure?
>>
>> Dave
>>
>>
>>
>> On Sat, Feb 3, 2018 at 10:41 AM, Dan CaJacob via USRP-users
>>  wrote:
>> > I saw no improvement when including a 3dB 50 Ohm attenuator as part of
>> the
>> > B200 NF meter. I guess I could try higher attenuator values.
>> >
>> > On Thu, Feb 1, 2018 at 9:16 PM Dan CaJacob 
>> wrote:
>> >>
>> >> I was gonna say, there's actually three of them ;)
>> >>
>> >>
>> >> On Thu, Feb 1, 2018, 9:06 PM Robin Coxe via USRP-users
>> >>  wrote:
>> >>>
>> >>> On p.8 of B200 schematic:
>> >>> T801 is Macom ETC1-1-13TR (RF2)
>> >>> T800 is Minicircuits TC1-1-43A+ (RF3)
>> >>> U802 is Anaren BD3150L50100AHF (RF1)
>> >>>
>> >>> On Thu, Feb 1, 2018 at 5:45 PM, Ron Economos via USRP-users
>> >>>  wrote:
>> 
>>  There's also a balun on the AD9361 input. Unfortunately, the balun
>> part
>>  number for the low frequency path is not on the schematic.
>> 
>>  Ron
>> 
>>  On 02/01/2018 05:39 PM, Dan CaJacob via USRP-users wrote:
>> 
>>  That's an interesting thought. The 9361 does have a pretty bad match.
>>  I'll try adding a 50 Ohm attenuator and see if that helps.
>> 
>>  On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe 
>> wrote:
>> >
>> > Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361
>> RF
>> > integrated transceiver. This chip does have an integrated LNA.
>>  Perhaps
>> > there's some sort of mismatch between your DUTs and this integrated
>> LNA at
>> > <1 GHz?
>> >
>> > ADI publishes the RX S-parameters:
>> > https://ez.analog.com/thread/41208#137929
>> >
>> > -Robin
>> >
>> > On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users
>> >  wrote:
>> >>
>> >> Hey guys,
>> >>
>> >> I have put together a noise figure meter application that uses a
>> USRP
>> >> as the sensing device. It started off as a way to measure the NF
>> of the USRP
>> >> itself. I have a calibrated noise source from an HP 8970B Noise
>> Figure
>> >> Meter. To test the NF of the USRP, I connect the head to the USRP
>> input. My
>> >> GNURadio flowgraph maximizes the USRP gain and measures a moving
>> average of
>> >> the received power while I switch the noise source on and off. The
>> >> difference in the received power level, in addition to the ENR
>> table from
>> >> the noise source, can then be used to calculate the NF of the USRP
>> itself
>> >> using the y-factor method.
>> >>
>> >> Once you have the NF for the USRP at many frequencies (I test
>> every 50
>> >> MHz from 50 MHz - 6000 MHz), you can modify the same procedure to
>> test the
>> >> NF of a Device Under Test (DUT) which is connected between the
>> noise source
>> >> and the (now calibrated) USRP. You can use the USRP cal table we
>> generated
>> >> in the previous step to derive the NF of the DUT corrected for the
>> NF of the
>> >> USRP.
>> >>
>> >> In short, this all works incredibly well and garners very
>> repeatable
>> >> results. One complication is that you will see wild NF at certain
>> >> frequencies due to local interference like LTE and WIFI. I've also
>> compared
>> >> the results to that which the HP device measures and they're very
>> >> comparable. ... Except below ~ 1GHz.
>> >>
>> >> And here's the issue - I am seeing higher NF for DUTs below abou

Re: [USRP-users] B200 Noise Figure Meter

[Dan CaJacob via USRP-users]

Yep, I am aware of that document and I am using the Y-factor method.

The 3 dB attenuator was calibrated with the B200 - i.e. I measured the NF
of the USRP + 3dB attenuator as a system. That data then serves as the
calibration data to correct for it's contribution to the subsequent NF
measurement of the B200 + 3dB pad + DUT.

I saw the same poor performance below 1 GHz when using the 3dB pad.

On Sun, Feb 4, 2018 at 11:44 AM David Bengtson 
wrote:

> A 3dB attenuation will really improve the reflection coefficient.
> Using this calculator
>
> http://www.rfcafe.com/references/calculators/vswr-return-loss-conversion-calculator.htm
> you can see that a 3 dB attenuation will improve a 3:1 VSWR to 1.7:2,
> or a 6 dB return loss to 12 dB, so you've really improved the match.
> The gory details of noise figure and match are in here
> http://literature.cdn.keysight.com/litweb/pdf/5952-3706E.pdf and
> Keysight has a spreadsheet to do the calculations here
>
> https://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=96887&nid=-34815.0.00&id=96887
> (Probably more detail than needed)
>
> Did you add the 3dB attenuator to the noise figure?
>
> Dave
>
>
>
> On Sat, Feb 3, 2018 at 10:41 AM, Dan CaJacob via USRP-users
>  wrote:
> > I saw no improvement when including a 3dB 50 Ohm attenuator as part of
> the
> > B200 NF meter. I guess I could try higher attenuator values.
> >
> > On Thu, Feb 1, 2018 at 9:16 PM Dan CaJacob 
> wrote:
> >>
> >> I was gonna say, there's actually three of them ;)
> >>
> >>
> >> On Thu, Feb 1, 2018, 9:06 PM Robin Coxe via USRP-users
> >>  wrote:
> >>>
> >>> On p.8 of B200 schematic:
> >>> T801 is Macom ETC1-1-13TR (RF2)
> >>> T800 is Minicircuits TC1-1-43A+ (RF3)
> >>> U802 is Anaren BD3150L50100AHF (RF1)
> >>>
> >>> On Thu, Feb 1, 2018 at 5:45 PM, Ron Economos via USRP-users
> >>>  wrote:
> 
>  There's also a balun on the AD9361 input. Unfortunately, the balun
> part
>  number for the low frequency path is not on the schematic.
> 
>  Ron
> 
>  On 02/01/2018 05:39 PM, Dan CaJacob via USRP-users wrote:
> 
>  That's an interesting thought. The 9361 does have a pretty bad match.
>  I'll try adding a 50 Ohm attenuator and see if that helps.
> 
>  On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe 
> wrote:
> >
> > Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361 RF
> > integrated transceiver. This chip does have an integrated LNA.
>  Perhaps
> > there's some sort of mismatch between your DUTs and this integrated
> LNA at
> > <1 GHz?
> >
> > ADI publishes the RX S-parameters:
> > https://ez.analog.com/thread/41208#137929
> >
> > -Robin
> >
> > On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users
> >  wrote:
> >>
> >> Hey guys,
> >>
> >> I have put together a noise figure meter application that uses a
> USRP
> >> as the sensing device. It started off as a way to measure the NF of
> the USRP
> >> itself. I have a calibrated noise source from an HP 8970B Noise
> Figure
> >> Meter. To test the NF of the USRP, I connect the head to the USRP
> input. My
> >> GNURadio flowgraph maximizes the USRP gain and measures a moving
> average of
> >> the received power while I switch the noise source on and off. The
> >> difference in the received power level, in addition to the ENR
> table from
> >> the noise source, can then be used to calculate the NF of the USRP
> itself
> >> using the y-factor method.
> >>
> >> Once you have the NF for the USRP at many frequencies (I test every
> 50
> >> MHz from 50 MHz - 6000 MHz), you can modify the same procedure to
> test the
> >> NF of a Device Under Test (DUT) which is connected between the
> noise source
> >> and the (now calibrated) USRP. You can use the USRP cal table we
> generated
> >> in the previous step to derive the NF of the DUT corrected for the
> NF of the
> >> USRP.
> >>
> >> In short, this all works incredibly well and garners very repeatable
> >> results. One complication is that you will see wild NF at certain
> >> frequencies due to local interference like LTE and WIFI. I've also
> compared
> >> the results to that which the HP device measures and they're very
> >> comparable. ... Except below ~ 1GHz.
> >>
> >> And here's the issue - I am seeing higher NF for DUTs below about
> 1GHz
> >> and particularly worse below 500 MHz. I was hoping someone at Ettus
> might be
> >> able to shed some light on why this might be. Curiously, the USRPs
> NF
> >> doesn't seem to be too bad, just the DUT.
> >>
> >> I'll note that I am nominally using a B200 for these tests, but I
> also
> >> tried an E312 just in case the filter banks might help out somehow.
> I didn't
> >> see a difference - they both had the same problem.
> >>
> >> I have used several DUTs for this test, including LNA boards we have
> >> des

Re: [USRP-users] B200 Noise Figure Meter

[David Bengtson via USRP-users]

A 3dB attenuation will really improve the reflection coefficient.
Using this calculator
http://www.rfcafe.com/references/calculators/vswr-return-loss-conversion-calculator.htm
you can see that a 3 dB attenuation will improve a 3:1 VSWR to 1.7:2,
or a 6 dB return loss to 12 dB, so you've really improved the match.
The gory details of noise figure and match are in here
http://literature.cdn.keysight.com/litweb/pdf/5952-3706E.pdf and
Keysight has a spreadsheet to do the calculations here
https://www.keysight.com/main/editorial.jspx?cc=US&lc=eng&ckey=96887&nid=-34815.0.00&id=96887
(Probably more detail than needed)

Did you add the 3dB attenuator to the noise figure?

Dave



On Sat, Feb 3, 2018 at 10:41 AM, Dan CaJacob via USRP-users
 wrote:
> I saw no improvement when including a 3dB 50 Ohm attenuator as part of the
> B200 NF meter. I guess I could try higher attenuator values.
>
> On Thu, Feb 1, 2018 at 9:16 PM Dan CaJacob  wrote:
>>
>> I was gonna say, there's actually three of them ;)
>>
>>
>> On Thu, Feb 1, 2018, 9:06 PM Robin Coxe via USRP-users
>>  wrote:
>>>
>>> On p.8 of B200 schematic:
>>> T801 is Macom ETC1-1-13TR (RF2)
>>> T800 is Minicircuits TC1-1-43A+ (RF3)
>>> U802 is Anaren BD3150L50100AHF (RF1)
>>>
>>> On Thu, Feb 1, 2018 at 5:45 PM, Ron Economos via USRP-users
>>>  wrote:

 There's also a balun on the AD9361 input. Unfortunately, the balun part
 number for the low frequency path is not on the schematic.

 Ron

 On 02/01/2018 05:39 PM, Dan CaJacob via USRP-users wrote:

 That's an interesting thought. The 9361 does have a pretty bad match.
 I'll try adding a 50 Ohm attenuator and see if that helps.

 On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe  wrote:
>
> Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361 RF
> integrated transceiver. This chip does have an integrated LNA.   Perhaps
> there's some sort of mismatch between your DUTs and this integrated LNA at
> <1 GHz?
>
> ADI publishes the RX S-parameters:
> https://ez.analog.com/thread/41208#137929
>
> -Robin
>
> On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users
>  wrote:
>>
>> Hey guys,
>>
>> I have put together a noise figure meter application that uses a USRP
>> as the sensing device. It started off as a way to measure the NF of the 
>> USRP
>> itself. I have a calibrated noise source from an HP 8970B Noise Figure
>> Meter. To test the NF of the USRP, I connect the head to the USRP input. 
>> My
>> GNURadio flowgraph maximizes the USRP gain and measures a moving average 
>> of
>> the received power while I switch the noise source on and off. The
>> difference in the received power level, in addition to the ENR table from
>> the noise source, can then be used to calculate the NF of the USRP itself
>> using the y-factor method.
>>
>> Once you have the NF for the USRP at many frequencies (I test every 50
>> MHz from 50 MHz - 6000 MHz), you can modify the same procedure to test 
>> the
>> NF of a Device Under Test (DUT) which is connected between the noise 
>> source
>> and the (now calibrated) USRP. You can use the USRP cal table we 
>> generated
>> in the previous step to derive the NF of the DUT corrected for the NF of 
>> the
>> USRP.
>>
>> In short, this all works incredibly well and garners very repeatable
>> results. One complication is that you will see wild NF at certain
>> frequencies due to local interference like LTE and WIFI. I've also 
>> compared
>> the results to that which the HP device measures and they're very
>> comparable. ... Except below ~ 1GHz.
>>
>> And here's the issue - I am seeing higher NF for DUTs below about 1GHz
>> and particularly worse below 500 MHz. I was hoping someone at Ettus 
>> might be
>> able to shed some light on why this might be. Curiously, the USRPs NF
>> doesn't seem to be too bad, just the DUT.
>>
>> I'll note that I am nominally using a B200 for these tests, but I also
>> tried an E312 just in case the filter banks might help out somehow. I 
>> didn't
>> see a difference - they both had the same problem.
>>
>> I have used several DUTs for this test, including LNA boards we have
>> designed ourselves and a Mini-Circuits ZX60-P103LN+
>> (https://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf). Both seem to 
>> exhibit
>> higher NF when measured with a USRP below 1 GHz. When testing them on 
>> the HP
>> NF meter, the NF is as expected all the way down to 50 MHz.
>>
>> I have attached the B200 cal data for your enjoyment as well as the
>> B200-measured ZX60 NF and the HP-measured ZX60. The HP NF meter only 
>> goes up
>> to 1600 MHz, which is why that data file stops there. I was surprised to 
>> see
>> the B200 seemed to have a better NF than the E

Re: [USRP-users] B200 Noise Figure Meter

[Dan CaJacob via USRP-users]

I saw no improvement when including a 3dB 50 Ohm attenuator as part of the
B200 NF meter. I guess I could try higher attenuator values.

On Thu, Feb 1, 2018 at 9:16 PM Dan CaJacob  wrote:

> I was gonna say, there's actually three of them ;)
>
> On Thu, Feb 1, 2018, 9:06 PM Robin Coxe via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
>> On p.8 of B200 schematic:
>> T801 is Macom ETC1-1-13TR (RF2)
>> T800 is Minicircuits TC1-1-43A+ (RF3)
>> U802 is Anaren BD3150L50100AHF (RF1)
>>
>> On Thu, Feb 1, 2018 at 5:45 PM, Ron Economos via USRP-users <
>> usrp-users@lists.ettus.com> wrote:
>>
>>> There's also a balun on the AD9361 input. Unfortunately, the balun part
>>> number for the low frequency path is not on the schematic.
>>>
>>> Ron
>>> On 02/01/2018 05:39 PM, Dan CaJacob via USRP-users wrote:
>>>
>>> That's an interesting thought. The 9361 does have a pretty bad match.
>>> I'll try adding a 50 Ohm attenuator and see if that helps.
>>>
>>> On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe  wrote:
>>>
 Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361 RF
 integrated transceiver. This chip does have an integrated LNA.   Perhaps
 there's some sort of mismatch between your DUTs and this integrated LNA at
 <1 GHz?

 ADI publishes the RX S-parameters:
 https://ez.analog.com/thread/41208#137929

 -Robin

 On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users <
 usrp-users@lists.ettus.com> wrote:

> Hey guys,
>
> I have put together a noise figure meter application that uses a USRP
> as the sensing device. It started off as a way to measure the NF of the
> USRP itself. I have a calibrated noise source from an HP 8970B Noise 
> Figure
> Meter. To test the NF of the USRP, I connect the head to the USRP input. 
> My
> GNURadio flowgraph maximizes the USRP gain and measures a moving average 
> of
> the received power while I switch the noise source on and off. The
> difference in the received power level, in addition to the ENR table from
> the noise source, can then be used to calculate the NF of the USRP itself
> using the y-factor method.
>
> Once you have the NF for the USRP at many frequencies (I test every 50
> MHz from 50 MHz - 6000 MHz), you can modify the same procedure to test the
> NF of a Device Under Test (DUT) which is connected between the noise 
> source
> and the (now calibrated) USRP. You can use the USRP cal table we generated
> in the previous step to derive the NF of the DUT corrected for the NF of
> the USRP.
>
> In short, this all works incredibly well and garners very repeatable
> results. One complication is that you will see wild NF at certain
> frequencies due to local interference like LTE and WIFI. I've also 
> compared
> the results to that which the HP device measures and they're very
> comparable. ... Except below ~ 1GHz.
>
> And here's the issue - I am seeing higher NF for DUTs below about 1GHz
> and particularly worse below 500 MHz. I was hoping someone at Ettus might
> be able to shed some light on why this might be. Curiously, the USRPs NF
> doesn't seem to be too bad, just the DUT.
>
> I'll note that I am nominally using a B200 for these tests, but I also
> tried an E312 just in case the filter banks might help out somehow. I
> didn't see a difference - they both had the same problem.
>
> I have used several DUTs for this test, including LNA boards we have
> designed ourselves and a Mini-Circuits ZX60-P103LN+ (
> https://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf). Both seem to
> exhibit higher NF when measured with a USRP below 1 GHz. When testing them
> on the HP NF meter, the NF is as expected all the way down to 50 MHz.
>
> I have attached the B200 cal data for your enjoyment as well as the
> B200-measured ZX60 NF and the HP-measured ZX60. The HP NF meter only goes
> up to 1600 MHz, which is why that data file stops there. I was surprised 
> to
> see the B200 seemed to have a better NF than the E312, which averaged 8 dB
> NF, by the way.
> --
> Very Respectfully,
>
> Dan CaJacob
>
> ___
> USRP-users mailing list
> USRP-users@lists.ettus.com
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>
>
 --
>>> Very Respectfully,
>>>
>>> Dan CaJacob
>>>
>>>
>>> ___
>>> USRP-users mailing 
>>> listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>
>>>
>>>
>>> ___
>>> USRP-users mailing list
>>> USRP-users@lists.ettus.com
>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>
>>>
>> ___
>> USRP-users mailing list
>> U

Re: [USRP-users] B200 Noise Figure Meter

[Dan CaJacob via USRP-users]

I was gonna say, there's actually three of them ;)

On Thu, Feb 1, 2018, 9:06 PM Robin Coxe via USRP-users <
usrp-users@lists.ettus.com> wrote:

> On p.8 of B200 schematic:
> T801 is Macom ETC1-1-13TR (RF2)
> T800 is Minicircuits TC1-1-43A+ (RF3)
> U802 is Anaren BD3150L50100AHF (RF1)
>
> On Thu, Feb 1, 2018 at 5:45 PM, Ron Economos via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
>> There's also a balun on the AD9361 input. Unfortunately, the balun part
>> number for the low frequency path is not on the schematic.
>>
>> Ron
>> On 02/01/2018 05:39 PM, Dan CaJacob via USRP-users wrote:
>>
>> That's an interesting thought. The 9361 does have a pretty bad match.
>> I'll try adding a 50 Ohm attenuator and see if that helps.
>>
>> On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe  wrote:
>>
>>> Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361 RF
>>> integrated transceiver. This chip does have an integrated LNA.   Perhaps
>>> there's some sort of mismatch between your DUTs and this integrated LNA at
>>> <1 GHz?
>>>
>>> ADI publishes the RX S-parameters:
>>> https://ez.analog.com/thread/41208#137929
>>>
>>> -Robin
>>>
>>> On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users <
>>> usrp-users@lists.ettus.com> wrote:
>>>
 Hey guys,

 I have put together a noise figure meter application that uses a USRP
 as the sensing device. It started off as a way to measure the NF of the
 USRP itself. I have a calibrated noise source from an HP 8970B Noise Figure
 Meter. To test the NF of the USRP, I connect the head to the USRP input. My
 GNURadio flowgraph maximizes the USRP gain and measures a moving average of
 the received power while I switch the noise source on and off. The
 difference in the received power level, in addition to the ENR table from
 the noise source, can then be used to calculate the NF of the USRP itself
 using the y-factor method.

 Once you have the NF for the USRP at many frequencies (I test every 50
 MHz from 50 MHz - 6000 MHz), you can modify the same procedure to test the
 NF of a Device Under Test (DUT) which is connected between the noise source
 and the (now calibrated) USRP. You can use the USRP cal table we generated
 in the previous step to derive the NF of the DUT corrected for the NF of
 the USRP.

 In short, this all works incredibly well and garners very repeatable
 results. One complication is that you will see wild NF at certain
 frequencies due to local interference like LTE and WIFI. I've also compared
 the results to that which the HP device measures and they're very
 comparable. ... Except below ~ 1GHz.

 And here's the issue - I am seeing higher NF for DUTs below about 1GHz
 and particularly worse below 500 MHz. I was hoping someone at Ettus might
 be able to shed some light on why this might be. Curiously, the USRPs NF
 doesn't seem to be too bad, just the DUT.

 I'll note that I am nominally using a B200 for these tests, but I also
 tried an E312 just in case the filter banks might help out somehow. I
 didn't see a difference - they both had the same problem.

 I have used several DUTs for this test, including LNA boards we have
 designed ourselves and a Mini-Circuits ZX60-P103LN+ (
 https://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf). Both seem to
 exhibit higher NF when measured with a USRP below 1 GHz. When testing them
 on the HP NF meter, the NF is as expected all the way down to 50 MHz.

 I have attached the B200 cal data for your enjoyment as well as the
 B200-measured ZX60 NF and the HP-measured ZX60. The HP NF meter only goes
 up to 1600 MHz, which is why that data file stops there. I was surprised to
 see the B200 seemed to have a better NF than the E312, which averaged 8 dB
 NF, by the way.
 --
 Very Respectfully,

 Dan CaJacob

 ___
 USRP-users mailing list
 USRP-users@lists.ettus.com
 http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com


>>> --
>> Very Respectfully,
>>
>> Dan CaJacob
>>
>>
>> ___
>> USRP-users mailing 
>> listUSRP-users@lists.ettus.comhttp://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
>>
>>
>> ___
>> USRP-users mailing list
>> USRP-users@lists.ettus.com
>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
>>
> ___
> USRP-users mailing list
> USRP-users@lists.ettus.com
> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>


-- 
Very Respectfully,

Dan CaJacob
___
USRP-users mailing list
USRP-users@lists.ettus.com
http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com

Re: [USRP-users] B200 Noise Figure Meter

[Robin Coxe via USRP-users]

On p.8 of B200 schematic:
T801 is Macom ETC1-1-13TR (RF2)
T800 is Minicircuits TC1-1-43A+ (RF3)
U802 is Anaren BD3150L50100AHF (RF1)

On Thu, Feb 1, 2018 at 5:45 PM, Ron Economos via USRP-users <
usrp-users@lists.ettus.com> wrote:

> There's also a balun on the AD9361 input. Unfortunately, the balun part
> number for the low frequency path is not on the schematic.
>
> Ron
> On 02/01/2018 05:39 PM, Dan CaJacob via USRP-users wrote:
>
> That's an interesting thought. The 9361 does have a pretty bad match. I'll
> try adding a 50 Ohm attenuator and see if that helps.
>
> On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe  wrote:
>
>> Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361 RF
>> integrated transceiver. This chip does have an integrated LNA.   Perhaps
>> there's some sort of mismatch between your DUTs and this integrated LNA at
>> <1 GHz?
>>
>> ADI publishes the RX S-parameters:  https://ez.
>> analog.com/thread/41208#137929
>>
>> -Robin
>>
>> On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users <
>> usrp-users@lists.ettus.com> wrote:
>>
>>> Hey guys,
>>>
>>> I have put together a noise figure meter application that uses a USRP as
>>> the sensing device. It started off as a way to measure the NF of the USRP
>>> itself. I have a calibrated noise source from an HP 8970B Noise Figure
>>> Meter. To test the NF of the USRP, I connect the head to the USRP input. My
>>> GNURadio flowgraph maximizes the USRP gain and measures a moving average of
>>> the received power while I switch the noise source on and off. The
>>> difference in the received power level, in addition to the ENR table from
>>> the noise source, can then be used to calculate the NF of the USRP itself
>>> using the y-factor method.
>>>
>>> Once you have the NF for the USRP at many frequencies (I test every 50
>>> MHz from 50 MHz - 6000 MHz), you can modify the same procedure to test the
>>> NF of a Device Under Test (DUT) which is connected between the noise source
>>> and the (now calibrated) USRP. You can use the USRP cal table we generated
>>> in the previous step to derive the NF of the DUT corrected for the NF of
>>> the USRP.
>>>
>>> In short, this all works incredibly well and garners very repeatable
>>> results. One complication is that you will see wild NF at certain
>>> frequencies due to local interference like LTE and WIFI. I've also compared
>>> the results to that which the HP device measures and they're very
>>> comparable. ... Except below ~ 1GHz.
>>>
>>> And here's the issue - I am seeing higher NF for DUTs below about 1GHz
>>> and particularly worse below 500 MHz. I was hoping someone at Ettus might
>>> be able to shed some light on why this might be. Curiously, the USRPs NF
>>> doesn't seem to be too bad, just the DUT.
>>>
>>> I'll note that I am nominally using a B200 for these tests, but I also
>>> tried an E312 just in case the filter banks might help out somehow. I
>>> didn't see a difference - they both had the same problem.
>>>
>>> I have used several DUTs for this test, including LNA boards we have
>>> designed ourselves and a Mini-Circuits ZX60-P103LN+ (
>>> https://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf). Both seem to
>>> exhibit higher NF when measured with a USRP below 1 GHz. When testing them
>>> on the HP NF meter, the NF is as expected all the way down to 50 MHz.
>>>
>>> I have attached the B200 cal data for your enjoyment as well as the
>>> B200-measured ZX60 NF and the HP-measured ZX60. The HP NF meter only goes
>>> up to 1600 MHz, which is why that data file stops there. I was surprised to
>>> see the B200 seemed to have a better NF than the E312, which averaged 8 dB
>>> NF, by the way.
>>> --
>>> Very Respectfully,
>>>
>>> Dan CaJacob
>>>
>>> ___
>>> USRP-users mailing list
>>> USRP-users@lists.ettus.com
>>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>>
>>>
>> --
> Very Respectfully,
>
> Dan CaJacob
>
>
> ___
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>
>
>
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Re: [USRP-users] B200 Noise Figure Meter

[Ron Economos via USRP-users]

There's also a balun on the AD9361 input. Unfortunately, the balun part 
number for the low frequency path is not on the schematic.


Ron

On 02/01/2018 05:39 PM, Dan CaJacob via USRP-users wrote:
That's an interesting thought. The 9361 does have a pretty bad match. 
I'll try adding a 50 Ohm attenuator and see if that helps.


On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe > wrote:


Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361
RF integrated transceiver. This chip does have an integrated LNA. 
 Perhaps there's some sort of mismatch between your DUTs and this
integrated LNA at <1 GHz?

ADI publishes the RX S-parameters:
https://ez.analog.com/thread/41208#137929

-Robin

On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users
mailto:usrp-users@lists.ettus.com>>
wrote:

Hey guys,

I have put together a noise figure meter application that uses
a USRP as the sensing device. It started off as a way to
measure the NF of the USRP itself. I have a calibrated noise
source from an HP 8970B Noise Figure Meter. To test the NF of
the USRP, I connect the head to the USRP input. My GNURadio
flowgraph maximizes the USRP gain and measures a moving
average of the received power while I switch the noise source
on and off. The difference in the received power level, in
addition to the ENR table from the noise source, can then be
used to calculate the NF of the USRP itself using the y-factor
method.

Once you have the NF for the USRP at many frequencies (I test
every 50 MHz from 50 MHz - 6000 MHz), you can modify the same
procedure to test the NF of a Device Under Test (DUT) which is
connected between the noise source and the (now calibrated)
USRP. You can use the USRP cal table we generated in the
previous step to derive the NF of the DUT corrected for the NF
of the USRP.

In short, this all works incredibly well and garners very
repeatable results. One complication is that you will see wild
NF at certain frequencies due to local interference like LTE
and WIFI. I've also compared the results to that which the HP
device measures and they're very comparable. ... Except below
~ 1GHz.

And here's the issue - I am seeing higher NF for DUTs below
about 1GHz and particularly worse below 500 MHz. I was hoping
someone at Ettus might be able to shed some light on why this
might be. Curiously, the USRPs NF doesn't seem to be too bad,
just the DUT.

I'll note that I am nominally using a B200 for these tests,
but I also tried an E312 just in case the filter banks might
help out somehow. I didn't see a difference - they both had
the same problem.

I have used several DUTs for this test, including LNA boards
we have designed ourselves and a Mini-Circuits ZX60-P103LN+
(https://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf). Both
seem to exhibit higher NF when measured with a USRP below 1
GHz. When testing them on the HP NF meter, the NF is as
expected all the way down to 50 MHz.

I have attached the B200 cal data for your enjoyment as well
as the B200-measured ZX60 NF and the HP-measured ZX60. The HP
NF meter only goes up to 1600 MHz, which is why that data file
stops there. I was surprised to see the B200 seemed to have a
better NF than the E312, which averaged 8 dB NF, by the way.
-- 
Very Respectfully,


Dan CaJacob

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--
Very Respectfully,

Dan CaJacob


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Re: [USRP-users] B200 Noise Figure Meter

[Dan CaJacob via USRP-users]

That's an interesting thought. The 9361 does have a pretty bad match. I'll
try adding a 50 Ohm attenuator and see if that helps.

On Thu, Feb 1, 2018 at 5:14 PM Robin Coxe  wrote:

> Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361 RF
> integrated transceiver. This chip does have an integrated LNA.   Perhaps
> there's some sort of mismatch between your DUTs and this integrated LNA at
> <1 GHz?
>
> ADI publishes the RX S-parameters:
> https://ez.analog.com/thread/41208#137929
>
> -Robin
>
> On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users <
> usrp-users@lists.ettus.com> wrote:
>
>> Hey guys,
>>
>> I have put together a noise figure meter application that uses a USRP as
>> the sensing device. It started off as a way to measure the NF of the USRP
>> itself. I have a calibrated noise source from an HP 8970B Noise Figure
>> Meter. To test the NF of the USRP, I connect the head to the USRP input. My
>> GNURadio flowgraph maximizes the USRP gain and measures a moving average of
>> the received power while I switch the noise source on and off. The
>> difference in the received power level, in addition to the ENR table from
>> the noise source, can then be used to calculate the NF of the USRP itself
>> using the y-factor method.
>>
>> Once you have the NF for the USRP at many frequencies (I test every 50
>> MHz from 50 MHz - 6000 MHz), you can modify the same procedure to test the
>> NF of a Device Under Test (DUT) which is connected between the noise source
>> and the (now calibrated) USRP. You can use the USRP cal table we generated
>> in the previous step to derive the NF of the DUT corrected for the NF of
>> the USRP.
>>
>> In short, this all works incredibly well and garners very repeatable
>> results. One complication is that you will see wild NF at certain
>> frequencies due to local interference like LTE and WIFI. I've also compared
>> the results to that which the HP device measures and they're very
>> comparable. ... Except below ~ 1GHz.
>>
>> And here's the issue - I am seeing higher NF for DUTs below about 1GHz
>> and particularly worse below 500 MHz. I was hoping someone at Ettus might
>> be able to shed some light on why this might be. Curiously, the USRPs NF
>> doesn't seem to be too bad, just the DUT.
>>
>> I'll note that I am nominally using a B200 for these tests, but I also
>> tried an E312 just in case the filter banks might help out somehow. I
>> didn't see a difference - they both had the same problem.
>>
>> I have used several DUTs for this test, including LNA boards we have
>> designed ourselves and a Mini-Circuits ZX60-P103LN+ (
>> https://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf). Both seem to
>> exhibit higher NF when measured with a USRP below 1 GHz. When testing them
>> on the HP NF meter, the NF is as expected all the way down to 50 MHz.
>>
>> I have attached the B200 cal data for your enjoyment as well as the
>> B200-measured ZX60 NF and the HP-measured ZX60. The HP NF meter only goes
>> up to 1600 MHz, which is why that data file stops there. I was surprised to
>> see the B200 seemed to have a better NF than the E312, which averaged 8 dB
>> NF, by the way.
>> --
>> Very Respectfully,
>>
>> Dan CaJacob
>>
>> ___
>> USRP-users mailing list
>> USRP-users@lists.ettus.com
>> http://lists.ettus.com/mailman/listinfo/usrp-users_lists.ettus.com
>>
>>
> --
Very Respectfully,

Dan CaJacob
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Re: [USRP-users] B200 Noise Figure Meter

[Robin Coxe via USRP-users]

Hi Dan.   Both the B200 and the E312 use the Analog Devices AD9361 RF
integrated transceiver. This chip does have an integrated LNA.   Perhaps
there's some sort of mismatch between your DUTs and this integrated LNA at
<1 GHz?

ADI publishes the RX S-parameters:
https://ez.analog.com/thread/41208#137929

-Robin

On Thu, Feb 1, 2018 at 7:46 AM, Dan CaJacob via USRP-users <
usrp-users@lists.ettus.com> wrote:

> Hey guys,
>
> I have put together a noise figure meter application that uses a USRP as
> the sensing device. It started off as a way to measure the NF of the USRP
> itself. I have a calibrated noise source from an HP 8970B Noise Figure
> Meter. To test the NF of the USRP, I connect the head to the USRP input. My
> GNURadio flowgraph maximizes the USRP gain and measures a moving average of
> the received power while I switch the noise source on and off. The
> difference in the received power level, in addition to the ENR table from
> the noise source, can then be used to calculate the NF of the USRP itself
> using the y-factor method.
>
> Once you have the NF for the USRP at many frequencies (I test every 50 MHz
> from 50 MHz - 6000 MHz), you can modify the same procedure to test the NF
> of a Device Under Test (DUT) which is connected between the noise source
> and the (now calibrated) USRP. You can use the USRP cal table we generated
> in the previous step to derive the NF of the DUT corrected for the NF of
> the USRP.
>
> In short, this all works incredibly well and garners very repeatable
> results. One complication is that you will see wild NF at certain
> frequencies due to local interference like LTE and WIFI. I've also compared
> the results to that which the HP device measures and they're very
> comparable. ... Except below ~ 1GHz.
>
> And here's the issue - I am seeing higher NF for DUTs below about 1GHz and
> particularly worse below 500 MHz. I was hoping someone at Ettus might be
> able to shed some light on why this might be. Curiously, the USRPs NF
> doesn't seem to be too bad, just the DUT.
>
> I'll note that I am nominally using a B200 for these tests, but I also
> tried an E312 just in case the filter banks might help out somehow. I
> didn't see a difference - they both had the same problem.
>
> I have used several DUTs for this test, including LNA boards we have
> designed ourselves and a Mini-Circuits ZX60-P103LN+ (
> https://www.minicircuits.com/pdfs/ZX60-P103LN+.pdf). Both seem to exhibit
> higher NF when measured with a USRP below 1 GHz. When testing them on the
> HP NF meter, the NF is as expected all the way down to 50 MHz.
>
> I have attached the B200 cal data for your enjoyment as well as the
> B200-measured ZX60 NF and the HP-measured ZX60. The HP NF meter only goes
> up to 1600 MHz, which is why that data file stops there. I was surprised to
> see the B200 seemed to have a better NF than the E312, which averaged 8 dB
> NF, by the way.
> --
> Very Respectfully,
>
> Dan CaJacob
>
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>
>
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