Q & A with Vaunix: Signal Fades and Dropouts with 3G Transceiver

In our Q & A blog series, we've addressed some of the most important and technical questions about our Lab Bricks. We hope these answers give you a better understanding of how our products work.

Q. We need to be able to simulate signal fades and dropouts for products with an embedded 3G transceiver. I have been looking at the LDA-302P-2 product as we need to be able to test up to 2600MHz and it needs to be able to handle a transmit power of 2W. We're not really sure how much attenuation we are likely to need to produce signal dropouts, would you think that 90dB would be sufficient? Is this model the most suitable for our requirements?

A. The LDA-302P-2 is certainly the attenuator that we would recommend. I'm not sure if this is going to get you enough range to cause dropouts. It really depends on the sensitivity of the receiver that you are using. I would guess the receiver sensitivity is around -90 dBm or better. If this is the case, you may need 2 attenuators. Possibly a 302P-1 and a 302P-2.

Q. I will check the receiver sensitivity, if it is better than -90dBm we would probably look at getting a fixed attenuator and putting that in series with the LDA-302P-2. Do you also sell fixed attenuators?

A. We do not sell fixed attenuators, but I'm sure you can find them. If you need help with this, we could source them for you. The estimated price would be $40 to $50. If you wanted additional control range, you could get 2 fixed attenuators (maybe 6 dB or 10 dB each) and the LDA-602E. By putting a 6 dB fixed attenuator on each side of the attenuator it would bring the power to a safe level. This would give you 120 dB of control range. This unit is more expensive, but it does provide additional flexibility for fading tests.

If you have any questions about operating or programming Vaunix products or other topics, please contact our technical support team.