Re: [USRP-users] B200 Noise Figure Meter

2018-02-21 Thread 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 tot

Re: [USRP-users] B200 Noise Figure Meter

2018-02-04 Thread 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 o

Re: [USRP-users] B200 Noise Figure Meter

2018-02-04 Thread 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 impr

Re: [USRP-users] B200 Noise Figure Meter

2018-02-03 Thread 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-user

Re: [USRP-users] B200 Noise Figure Meter

2018-02-01 Thread 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, F

Re: [USRP-users] B200 Noise Figure Meter

2018-02-01 Thread 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 balu

Re: [USRP-users] B200 Noise Figure Meter

2018-02-01 Thread 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 attenu

Re: [USRP-users] B200 Noise Figure Meter

2018-02-01 Thread 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

Re: [USRP-users] B200 Noise Figure Meter

2018-02-01 Thread 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#13