Measuring RF shielding cans of the MFAA LNA

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On the daily image of december 14th 2016 two different RF shielding cans for the MFAA LNA were shown. To see if there is a difference between the shielding properties of these shielding cans a measurement setup consisting of a waveguide was used to measure the shielding of them. To measure the shielding cans they were mounted on a PCB.

The first picture shows the measured PCB's with the shielding cans mounted on it. The open PCB and solid PCB were used for reference measurements. Shielding cans 2 and 4 are the ones that are shown in the daily image mentioned previously. Shielding can 1 is from another manufacturer. Shielding can 3 is the same as shielding can 4. Only the production process is different.

The second picture shows how a PCB is mounted in the measurement setup. The third picture shows the total measurement setup. The shielding of the different cans is determined by measuring the transfer function between the two connectors of the waveguide. By comparing the measured transfer function with the one of an open PCB without shielding can the shielding can be determined. The graph shows the measured transfer function with respect to the transfer function of an open PCB without can. One can see that the shielding below 4 GHz is around -30 dB for all cans. For higher frequencies resonances resonances occur in the transfer function. The conclusion is that there is no significant difference between the four shielding cans.