LabView

[sine_help]

Thanks for reply. we have all ESD protection measurments eg. ESD protective wrist strap, static dissipative table top, ESD protective floor mat. our ground has less than .5 ohms resistance. antenna is also grounded and enclosed in plastic casing. actually this damage is not first time . it happen second time even after these special arrangments. we are also using UPS of company APC.  system was working fine but suddenly it stop working. we have to find actual reason for that. also tell me if i want to use my sytem in moving  vehicle than how can i get grounded and how ESD protection will work.?

Is there any way that antenna has DC voltage on it. downconverter has max 0V dc at input. if system is working fine with antenna, what would be causes of sudden appearance of DC voltage on antenna like through induction etc?

Is there any relation of buring of Mixer ic with voltages on neutral terminal of power supply eg. if neutral to ground voltage is 5V or 10V can this burn MIXER IC at RF input? 

regards

[GovBob]

If you suspect DC is the problem might I suggest a DC block. I use the one from http://www.fairviewmicrowave.com/coaxial_dc_blocks.htm company.

Hope this helps

[sine_help]

Thanks for reply . Can any one answer other part of question regarding ESD and grounding in moving vehicle and WHY neutral to ground voltage should below 1V .how this affect RF input circuit?

regards

[chris_amadasun]

Hi,

There are a couple of reasons why this can happen through any combination of the following

1. The antenna might be coupled to something else (some other antenna in the car)

2. There is DC coming into the antenna input

3. High voltage spikes going in through the antenna which could be caused by addictive reflections.

Use a combination of the following

1. Use a DC blocker this will prevent a DC bias on the antenna input

2. Use an antenuator

3. Use a shielded antenna

[sine_help]

Thanks for reply. I am using NI PXIe 5663 6.6 GHz Vector Signal Analyzer. IF output range is 187.5MHz for 10MHz to 50Mhz bandwidth and 53MHz for 20MHz . it has no anti aliasing filter. thats why some aliased signals mix with desired signal . how can i solve this problem. one solution may be , is to bandpass filter the incoming signal or IF . if yes please mention how it works and recommanded bandpass filters with center frequency 187.5MHz ith bandwidth 10MHz to 50MHz and 53 MHz with bandwidth 20MHz.

[chris_amadasun]

Hi,

The IF frequency used by the 5663 depends on the frequency input.

In the range 10MHz-to-120MHz the IF frequency is 187.5MHz,

For 120MHz-to-330MHz the IF frequency is 187.5MHz

For 330MHz-to3.0GHz and 3.0GHz-to-6.6GHz the IF frequency is 187.5MHz

Here are some recommendations

1. Change between High and Low-Side injection. 
2. Use external filtering to eliminate any out-of-band RF signal that might be imaged into the IF passband.

The NI RF Vector Signal Analyzes Help manual has a very detailed section on LO Injection, open up the manual and search for "injection" w/o the quotes. Click on the LO Injuection Side topic.

Let me know if this helps

[sine_help]

Thanks for reply. You have suggested to "Use external filtering to eliminate any out-of-band RF signal that might be imaged into the IF passband". please guide me, what type of bandpass filter i should use. Is NI manufactures any external filter? also suggest filters of other brands.

regards 

[chris_amadasun]

Hello,

NI does not manufacture RF filter hardware (or any filters for that matter).

We do not have a particular manufacturer that we can recommend either. You can search on google for a manufacture so long as the device can provide 50 Ohms of impedance to match the inputs of the RFSA and antenna.

Have you tried LO injection?

Regards

[sine_help]

HI ,

  please guide me about data rates for following peer to peer streaming scenarios. assuming peer-peer communication support 800MB/s. Modules used are PXIe-5122, PXIe7966R,NI-8265(not peer-peer supported) and chasis PXIe 1075.

scenario 1: Data is streaming(peer-peer) from PXIe-5122 to two PXIe7966R at same time. all modules are connected through PCIe switch1 ie. slot 2,3,4,5. 

scenario 2: Data is streaming(peer-peer) from PXIe-5122 to two PXIe7966R and also to NI8265(not peer-peer supported)at same time . PXIe-5122, PXIe7966R, modules are connected through PCIe switch1 ie. slot 2,3,4,5 and NI-8265 is connected to slot 18 through PCIe switch 4. 

please tell me what will be data path for both scenarios and is there any role of controller memory for both streaming scenarios? what will be required bandwidths for both scenarios?

if i want to send data from NI-8265 to ethernet how data will flow in following cases.

1. raid to ethernet using controllers ethernet port

2. raid to ethernet using NI 8234( what are benefits of using it?)

Regards

[sine_help]

HI please also reply to my previous message  considering digitizer PXIe-5622

Regards