Analog Devices ADRV9001 User Manual page 246

Reference Manual ADRV9001
RF PORT INTERFACE INFORMATION
Figure 218. ADRV9001 Receiver B Port Series Equivalent Differential Impedance
Advanced Design System (ADS) Setup Using DAC and SEDZ File
Analog Devices supplies the port impedance as an *.s1p series equivalent differential Z (impedance) file. This format allows the simple
interface to the advanced design system (ADS) using the data access component (DAC). Term1 is the single-ended input or output and Term2
represents the differential input or output RF port on the ADRV9001. See Figure 219. The Pi on the single-ended side and the differential Pi
configuration on the differential side allow maximum flexibility in designing matching circuits, and is suggested for all design layouts as it can
step the impedance up or down as needed with the appropriate component population.
Figure 219. Simulation Setup in ADS with SEDZ S1P Files and DAC Component
The operation is as follows:
1. The DAC block reads the rf port*.s1p file. This is the device RF port reflection coefficient.
2. The two equations convert the RF port reflection coefficient to a complex impedance. The result is the RX_SEDZ variable.
3. The RF port calculated complex impedance (RX_SEDZ) defines the Term2 impedance.
a. Term2 is used in the differential mode and Term1 is used in the single-ended mode.
Setting up the simulation this way allows to measure the S11, S22, and S21 of the 3-port system without complex math operations within the
display page.
Note: For the highest accuracy, use the EM modeling result of the PCB artwork and S-parameters of the laminate (also supplied by Analog
Devices), matching components and balun in the simulations.
Insert the first differential shunt reactive component, such as L103 in Figure 219, to tune out the parallel parasitic reactance of the input
impedance of the device. If the AC-coupling cap is necessary, use C118 and C119.
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