The ADL8121-EVALZ consists of a 4-layer printed circuit board (PCB) fabricated from 10 mil thick, Rogers 4350B and Isola 370HR copper clad, forming a nominal thickness of 62 mils. The RFIN and RFOUT ports on the ADL8121-EVALZ are populated with Subminiature A (SMA) female coaxial connectors, and the corresponding RF traces have a 50 Ω characteristic impedance. The ADL8121-EVALZ is populated with components suitable for use over the entire −40°C to +85°C operating temperature range of the ADL8121. To calibrate board trace losses, a through calibration path is provided between the J1 and J2 connectors. J1 and J2 must be populated with RF connectors and capacitors to use the through calibration path. Refer Figure 3 to Table 1 and for the through calibration path performance.
Access the ADL8121-EVALZ ground path and RFOUT/VDD pin through the surface-mount technology (SMT) test point connectors, GND and VDD. A supplementary test point for VBIAS is included for simple access on the RBIAS pin (see Figure 5 in the user guide for the test point locations).
The RF traces on the ADL8121-EVALZ are 50 Ω, grounded coplanar waveguide. The package ground leads and the exposed pad connect directly to the ground plane. Multiple vias connect the top and bottom ground planes with particular focus on the area directly beneath the ground paddle to provide adequate electrical conduction and thermal conduction to the heat sink.
The power supply decoupling capacitors on the ADL8121-EVALZ represent the configuration used to characterize and qualify the device.
For full details on the ADL8121, see the ADL8121 data sheet, which must be consulted in conjunction with the user guide when using the ADL8121-EVALZ.
