Tool/software:
Hello,
I am wondering if there is existing reference design that has separated matching network for PA and LNA going into 50ohms. The reference designs I could find either used TRX_SW to connect both together; or uses an impedance matching device like LFD21868MMF1D386.
For LNA input, based on the datasheet with desinators from SWRR121, I am getting L191 = 20.87nH, L192 = L201 = 13.47nH, C191 = C201 = 2.25pF. These values are close to the values from the reference design L191 = 15nH, L192 = L201 = 12nH, C191 = C201 = 3.3pF, that I want to assume the value looking towards LNA from L193 was tuned on the reference design to be 50ohms, adjusting for the physical layouts and such. Is this assumption correct?
For PA, I see in multiple reference designs that its biasing path contains a parallel 10R resistor and 33pF capacitor, which is not really explained in the datasheet. Are these RC network required for its DC biasing? A simple T network with bias to VCC would not have these RC for example.
Best