Interference from SDRAM

[stephen168]

I am debuging the low sensitivity of the WiFi from our product. There is a SDRAM inside the product and the SW is running inside the SDRAM. The DSP and SDRAM are put inside the shielding can, it worked very well. Recently, we changed the SDRAM from brand A to brand B, the sensitivity of WiFi is degraded by 10dB. Provided that the SW is same, the clock rate is same. When I swap the old SDRAM to it, the sensitivty is as good as before.
According to the data sheet, they are nearly the same. The current consumption from brand B(poorer sens) SDRAM is 20% higher during accessing by measurement.
Does anyone know what make it so different for interference?

 

[VEBill]

Double-posting is frowned upon. I've responded on the Antennas & Propagation thread.