LNA case (ref. AN APS004)

Wireless Connectivity Ultra-Wideband
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[color=#222222][size=small][font=Arial, Helvetica, sans-serif]Hi All![/font][/size][/color]

[color=#222222][size=small][font=Arial, Helvetica, sans-serif]We’ve successfully tested RX, magnified by Infineon’s LNA and here are couple questions have risen:[/font][/size][/color]

[color=#222222][size=small][font=Arial, Helvetica, sans-serif]1. What kind of troubles we’ll face in the case, when attenuator had been wrongly chosen? (assuming worst case, it is 0dB) and distance between emitting and receiving devices are pretty small.[/font][/size][/color]
[color=#222222][size=small][font=Arial, Helvetica, sans-serif]AN mentions packet losses and “compression”. Will accumulated compression degrade the life time for DW1000?[/font][/size][/color]

[color=#222222][size=small][font=Arial, Helvetica, sans-serif]2. Infineon’s LNA has On-Off switch onboard and, assuming we control it, will RX timestamp for packets received with LNA turned On and Off differ somehow in respect to antenna delay parameter?[/font][/size][/color]
[color=#222222][size=small][font=Arial, Helvetica, sans-serif]I can confirm, that with LNA switched off we still receive packets, but with dramatically shorter distance between anchor an tag.[/font][/size][/color]

[color=#222222][size=small][font=Arial, Helvetica, sans-serif]3. AN suggests RF switches for RX/TX path alternating, but what if we’ll try to transmit over RX path with LNA turned off? How penalty will look like?[/font][/size][/color]

[color=#222222][size=small][font=Arial, Helvetica, sans-serif]Stan[/font][/size][/color]

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Hi All!

We’ve successfully tested RX, magnified by Infineon’s LNA and here are couple questions have risen:

  1. What kind of troubles we’ll face in the case, when attenuator had been wrongly chosen? (assuming worst case, it is 0dB) and distance between emitting and receiving devices are pretty small.
    AN mentions packet losses and “compression”. Will accumulated compression degrade the life time for DW1000?

  2. Infineon’s LNA has On-Off switch onboard and, assuming we control it, will RX timestamp for packets received with LNA turned On and Off differ somehow in respect to antenna delay parameter?
    I can confirm, that with LNA switched off we still receive packets, but with dramatically shorter distance between anchor an tag.

  3. AN suggests RF switches for RX/TX path alternating, but what if we’ll try to transmit over RX path with LNA turned off? How penalty will look like?

Stan

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Hi Stan,

could you send more informations regarding LNA? Type, schematics, etc…

best Regards,
Irek

4

but in the board we used 27pf CAPs in RF track (not 100pf, as in the attachment), as per subject AN

5

Further, I can report, that we couldn’t witness packet losses even with LNA turned On and attenuator 3dB with distance less than couple meters between RX and TX sites…
Both sites equipped with WB002 PCB antenna (as per vendor’s recommendations and footprints)