usrp-users@lists.ettus.com
Discussion and technical support related to USRP, UHD, RFNoC
View all threadsX440 Phase Coherent but not Phase Aligned
On 27/03/2025 15:31, Mann, John - 0662 - MITLL wrote:
Does anyone know if there is a way to get predictable phase offsets
from an X410? I am finding that from run-to-run, the 4 channels in an
X410 have completely random phase offsets from each other. I didn’t
necessarily expect the phase offsets to be zero, but was hoping they
would at least be consistent.
John
At the very least, use timed-commands to tune it. The ZBX board that
does the analog up/down conversion uses LMX2572
synthesizers, and I don't know how easy it is to phase-align those
synthesizers in practice.
From: Chris Rogers c1337rogers@gmail.com
Sent: Thursday, March 27, 2025 1:51 PM
To: Marcus D. Leech patchvonbraun@gmail.com
Cc: usrp-users@lists.ettus.com
Subject: [EXT] [USRP-users] Re: X440 Phase Coherent but not Phase
Aligned
Hi Heath and Marcus, I was actually "R&D's plate" for this one. We
worked through it and found the issue. The root cause is the startup
sequence in almost every example UHD script is a bit out of order and
had to be reorganized
ZjQcmQRYFpfptBannerStart
*This Message Is From an External Sender *
This message came from outside the Laboratory.
ZjQcmQRYFpfptBannerEnd
Hi Heath and Marcus,
I was actually "R&D's plate" for this one. We worked through it and
found the issue. The root cause is the startup sequence in almost
every example UHD script is a bit out of order and had to be
reorganized in terms of clock setup and synchronized channel tuning.
This problem is fixed in UHD 4.7+ if you look at the
"tx_waveforms.cpp" example code... For your application, just make
sure to follow the same startup sequence.
Hope this helps,
Chris
USRP-users mailing list --usrp-users@lists.ettus.com
To unsubscribe send an email tousrp-users-leave@lists.ettus.com
Hi,
What is the max input signal power to RF ports in X310? There is a spec in the below link:https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdfThere are max output powers, but not input power.
I am using UBX-160 daughterboard.
In https://kb.ettus.com/X300/X310_Getting_Started_Guides, it says that"Never apply more than -15 dBm of power into any RF input."
ChatGpt says that "UBX 40: +10 dBm (10 mW)"
What is the max input signal power?
Thanks for any comments,
Zhou
On 31/03/2025 11:51, zhou via USRP-users wrote:
Hi,
What is the max input signal power to RF ports in X310? There is a
spec in the below link:
https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf
There are max output powers, but not input power.
I am using UBX-160 daughterboard.
In https://kb.ettus.com/X300/X310_Getting_Started_Guides, it says that
"Never apply more than -15 dBm of power into any RF input."
ChatGpt says that "UBX 40: +10 dBm (10 mW)"
What is the max input signal power?
Thanks for any comments,
Zhou
-15dBm is somewhat conservative, but if that's what the manufacturer
recommends, I'd go with that, rather than a
hallucination produced by ChatGPT.
The receivers on USRPs are generally designed to be connected to an
antenna, and as such have sensitive, lower-noise
front-ends. Such front-ends generally don't tolerate higher input
powers without damage--and +10dBm IS high
input power for a radio receiver.
One may have gotten used to the relatively-insensitive inputs of
laboratory spectrum analyzers, which often have
inputs that can tolerate considerably-higher power levels, but are
insensitive at levels expected from direct
connection to an antenna. But USRPs are designed for antenna
connection. If you want to use them as
a laboratory spectrum analyser, you'll need to use attenuators.
USRP-users mailing list --usrp-users@lists.ettus.com
To unsubscribe send an email tousrp-users-leave@lists.ettus.com
Just to follow on. The BasicRx is +10 dBm. I've been using that as a max to
the BasicRx for quite a while without issue. But the UBX-160 knowledge base
indicates -15 dBm. I'd assume if you're using the UBX that you'll be using
the configurable on-board amplification (up to 31.5 dB).
On Mon, Mar 31, 2025, 8:59 AM Marcus D. Leech patchvonbraun@gmail.com
wrote:
On 31/03/2025 11:51, zhou via USRP-users wrote:
Hi,
What is the max input signal power to RF ports in X310? There is a spec
in the below link:
https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf
There are max output powers, but not input power.
I am using UBX-160 daughterboard.
In https://kb.ettus.com/X300/X310_Getting_Started_Guides, it says that
"Never apply more than -15 dBm of power into any RF input."
ChatGpt says that "UBX 40: +10 dBm (10 mW)"
What is the max input signal power?
Thanks for any comments,
Zhou
-15dBm is somewhat conservative, but if that's what the manufacturer
recommends, I'd go with that, rather than a
hallucination produced by ChatGPT.
The receivers on USRPs are generally designed to be connected to an
antenna, and as such have sensitive, lower-noise
front-ends. Such front-ends generally don't tolerate higher input
powers without damage--and +10dBm IS high
input power for a radio receiver.
One may have gotten used to the relatively-insensitive inputs of
laboratory spectrum analyzers, which often have
inputs that can tolerate considerably-higher power levels, but are
insensitive at levels expected from direct
connection to an antenna. But USRPs are designed for antenna
connection. If you want to use them as
a laboratory spectrum analyser, you'll need to use attenuators.
USRP-users mailing list -- usrp-users@lists.ettus.com
To unsubscribe send an email to usrp-users-leave@lists.ettus.com
USRP-users mailing list -- usrp-users@lists.ettus.com
To unsubscribe send an email to usrp-users-leave@lists.ettus.com
Also notice that the input power to the X310 (the ADC described
in the first link) might not be relevant to the UBX-160 daughter board
input with its preamplifier and mixer or RF frontend in general.
With a BasicRX (ie balun -> ADC direct connection, no frontend/mixer/preamp)
I have measured the ADC output amplitude to input amplitude to be linear up to
+6 dBm input power, which I use with synthetic data generated from an FPGA
for best SNR with no distorsion.
Best, JM
----- Mail original -----
De: "Marcus D. Leech" patchvonbraun@gmail.com
À: "usrp-users" usrp-users@lists.ettus.com
Envoyé: Lundi 31 Mars 2025 17:57:55
Objet: [USRP-users] Re: Max Input RF Power in X310
On 31/03/2025 11:51, zhou via USRP-users wrote:
Hi,
What is the max input signal power to RF ports in X310? There is a spec in the below link:
[ https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf | https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf ]
There are max output powers, but not input power.
I am using UBX-160 daughterboard.
In [ https://kb.ettus.com/X300/X310_Getting_Started_Guides | https://kb.ettus.com/X300/X310_Getting_Started_Guides ] , it says that
" Never apply more than -15 dBm of power into any RF input. "
ChatGpt says that " UBX 40 : +10 dBm (10 mW)"
What is the max input signal power?
Thanks for any comments,
Zhou
-15dBm is somewhat conservative, but if that's what the manufacturer recommends, I'd go with that, rather than a
hallucination produced by ChatGPT.
The receivers on USRPs are generally designed to be connected to an antenna, and as such have sensitive, lower-noise
front-ends. Such front-ends generally don't tolerate higher input powers without damage--and +10dBm IS high
input power for a radio receiver.
One may have gotten used to the relatively-insensitive inputs of laboratory spectrum analyzers, which often have
inputs that can tolerate considerably-higher power levels, but are insensitive at levels expected from direct
connection to an antenna. But USRPs are designed for antenna connection. If you want to use them as
a laboratory spectrum analyser, you'll need to use attenuators.
BQ_BEGIN
USRP-users mailing list -- [ mailto:usrp-users@lists.ettus.com | usrp-users@lists.ettus.com ] To unsubscribe send an email to [ mailto:usrp-users-leave@lists.ettus.com | usrp-users-leave@lists.ettus.com ]
BQ_END
USRP-users mailing list -- usrp-users@lists.ettus.com
To unsubscribe send an email to usrp-users-leave@lists.ettus.com
Hi Marcus,
Thanks for your quick response. I still have some doubt. In X410 spec, there is clear information on max input rf power: +14dBm for f<3GHz, +17dBm for f>3GHz
https://www.ni.com/docs/en-US/bundle/ettus-usrp-x410-specs/page/specs.html#GUID-50099182-F4E2-42EC-BBBD-7E336B07FFBE__GUID-B1D08221-A553-4A47-805A-896B34C98C07
If the max input signal power is -15dBm, the difference between X310 and X410 is too big.
Any further inputs will be appreciated.
On Monday 31 March 2025 at 16:59:11 BST, Marcus D. Leech <patchvonbraun@gmail.com> wrote:
On 31/03/2025 11:51, zhou via USRP-users wrote:
Hi,
What is the max input signal power to RF ports in X310? There is a spec in the below link: https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf There are max output powers, but not input power.
I am using UBX-160 daughterboard.
In X300/X310 Getting Started Guides - Ettus Knowledge Base, it says that
|
|
|
| | |
|
|
|
| |
X300/X310 Getting Started Guides - Ettus Knowledge Base
|
|
|
"Never apply more than -15 dBm of power into any RF input."
ChatGpt says that "UBX 40: +10 dBm (10 mW)"
What is the max input signal power?
Thanks for any comments,
Zhou
-15dBm is somewhat conservative, but if that's what the manufacturer recommends, I'd go with that, rather than a
hallucination produced by ChatGPT.
The receivers on USRPs are generally designed to be connected to an antenna, and as such have sensitive, lower-noise
front-ends. Such front-ends generally don't tolerate higher input powers without damage--and +10dBm IS high
input power for a radio receiver.
One may have gotten used to the relatively-insensitive inputs of laboratory spectrum analyzers, which often have
inputs that can tolerate considerably-higher power levels, but are insensitive at levels expected from direct
connection to an antenna. But USRPs are designed for antenna connection. If you want to use them as
a laboratory spectrum analyser, you'll need to use attenuators.
USRP-users mailing list -- usrp-users@lists.ettus.com
To unsubscribe send an email to usrp-users-leave@lists.ettus.com
USRP-users mailing list -- usrp-users@lists.ettus.com
To unsubscribe send an email to usrp-users-leave@lists.ettus.com
On 31/03/2025 12:09, Mark Gannet wrote:
Just to follow on. The BasicRx is +10 dBm. I've been using that as a
max to the BasicRx for quite a while without issue. But the UBX-160
knowledge base indicates -15 dBm. I'd assume if you're using the UBX
that you'll be using the configurable on-board amplification (up to
31.5 dB).
The basic_RX has NO analog gain elements at all. It's basically just a
transformer-coupling to the ADCs, so your limit is
the limit of the ADCs.
On Mon, Mar 31, 2025, 8:59 AM Marcus D. Leech
patchvonbraun@gmail.com wrote:
On 31/03/2025 11:51, zhou via USRP-users wrote:
Hi,
What is the max input signal power to RF ports in X310? There is
a spec in the below link:
https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf
There are max output powers, but not input power.
I am using UBX-160 daughterboard.
In https://kb.ettus.com/X300/X310_Getting_Started_Guides, it says
that
"Never apply more than -15 dBm of power into any RF input."
ChatGpt says that "*UBX 40*: *+10 dBm* (10 mW)"
What is the max input signal power?
Thanks for any comments,
Zhou
-15dBm is somewhat conservative, but if that's what the
manufacturer recommends, I'd go with that, rather than a
hallucination produced by ChatGPT.
The receivers on USRPs are generally designed to be connected to
an antenna, and as such have sensitive, lower-noise
front-ends. Such front-ends generally don't tolerate higher
input powers without damage--and +10dBm *IS* high
input power for a radio receiver.
One may have gotten used to the relatively-insensitive inputs of
laboratory spectrum analyzers, which often have
inputs that can tolerate considerably-higher power levels, but
are insensitive at levels expected from direct
connection to an antenna. But USRPs are designed for antenna
connection. If you want to use them as
a laboratory spectrum analyser, you'll need to use attenuators.
_______________________________________________
USRP-users mailing list --usrp-users@lists.ettus.com
To unsubscribe send an email tousrp-users-leave@lists.ettus.com
_______________________________________________
USRP-users mailing list -- usrp-users@lists.ettus.com
To unsubscribe send an email to usrp-users-leave@lists.ettus.com
On 31/03/2025 12:17, zhou via USRP-users wrote:
Hi Marcus,
Thanks for your quick response. I still have some doubt. In X410 spec,
there is clear information on max input rf power: +14dBm for f<3GHz,
+17dBm for f>3GHz
If the max input signal power is -15dBm, the difference between X310
and X410 is too big.
Any further inputs will be appreciated.
They are completely different designs, with completely different
components. The X410 uses Xilinx RFSoCs that have
integrated RF chains inside the chips.
Now, having said THAT, the UBX-160 has either an MGA62563 LNA chip or
PMA3-83LN LNA chip "up front", depending on
the selected frequency range. Both of these chips can tolerate
considerably higher input powers. However, that doesn't
mean that components that are downstream from those LNAs are going
to be happy seeing those high input powers
amplified by the font-end LNA. So, for the most part,
Ettus/NI/Emerson recommend no more than -15dBm as
a safe, conservative, value. In the intended application space,
where they are intended to be directly antenna-connected,
a signal of -15dBm is "blow the doors off" loud.
On Monday 31 March 2025 at 16:59:11 BST, Marcus D. Leech
patchvonbraun@gmail.com wrote:
On 31/03/2025 11:51, zhou via USRP-users wrote:
Hi,
What is the max input signal power to RF ports in X310? There is a
spec in the below link:
https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf
https://www.ettus.com/wp-content/uploads/2024/01/X300_X310_Spec_Sheet_2024-01-23.pdf
There are max output powers, but not input power.
I am using UBX-160 daughterboard.
In X300/X310 Getting Started Guides - Ettus Knowledge Base
https://kb.ettus.com/X300/X310_Getting_Started_Guides, it says that
X300/X310 Getting Started Guides - Ettus Knowledge Base
https://kb.ettus.com/X300/X310_Getting_Started_Guides
"Never apply more than -15 dBm of power into any RF input."
ChatGpt says that "UBX 40: +10 dBm (10 mW)"
What is the max input signal power?
Thanks for any comments,
Zhou
-15dBm is somewhat conservative, but if that's what the manufacturer
recommends, I'd go with that, rather than a
hallucination produced by ChatGPT.
The receivers on USRPs are generally designed to be connected to an
antenna, and as such have sensitive, lower-noise
front-ends. Such front-ends generally don't tolerate higher input
powers without damage--and +10dBm IS high
input power for a radio receiver.
One may have gotten used to the relatively-insensitive inputs of
laboratory spectrum analyzers, which often have
inputs that can tolerate considerably-higher power levels, but are
insensitive at levels expected from direct
connection to an antenna. But USRPs are designed for antenna
connection. If you want to use them as
a laboratory spectrum analyser, you'll need to use attenuators.
USRP-users mailing list --usrp-users@lists.ettus.com mailto:usrp-users@lists.ettus.com
To unsubscribe send an email tousrp-users-leave@lists.ettus.com mailto:usrp-users-leave@lists.ettus.com
USRP-users mailing list -- usrp-users@lists.ettus.com
To unsubscribe send an email to usrp-users-leave@lists.ettus.com
USRP-users mailing list --usrp-users@lists.ettus.com
To unsubscribe send an email tousrp-users-leave@lists.ettus.com