Infineon BGT24MTR11 mmic: should RF in/outs be decoupled from ground?
时间：04-04
整理：3721RD
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I am creating layout for testing BGT24MTR11. In my case RF in/outs must be connected to single ridge waveguides, through microstrip to waveguide transitions. So currently all microstrip paths are tied to ground.
I found two reference designs where:
1) Patch array do not have dc path to ground. In this case Rf in/outs either directly connect patch arrays.
2) Patch arrays have DC path to ground (probably ESD protection). In this case RF in/outs connected to patch arrays through microstrip DC block (coupled λ/4 lines). It makes me think that RF in/outs have some DC offset and could not be tied to ground (DC).
Although documentation states that:
Why there is DC block? (Sense2GoL demoboard). Can someone confirm that RF in/outs may be have direct connection to ground (outside of MMIC)?
I found two reference designs where:
1) Patch array do not have dc path to ground. In this case Rf in/outs either directly connect patch arrays.
2) Patch arrays have DC path to ground (probably ESD protection). In this case RF in/outs connected to patch arrays through microstrip DC block (coupled λ/4 lines). It makes me think that RF in/outs have some DC offset and could not be tied to ground (DC).
Although documentation states that:
Why there is DC block? (Sense2GoL demoboard). Can someone confirm that RF in/outs may be have direct connection to ground (outside of MMIC)?
Figure 7 of the data sheet shows an internal inductor to ground on on all RF connectionsn and as you say the absolute maximum rating gives 0V min/max for the RF pins. In that case it looks like the RF terminals should not be connected to any DC supply other than ground.
As the pins are already tied to ground floating should be OK so long as there is no chance of static discharge to them.