ADL8108

• 4-layer, Rogers 4350B and Isola 370HR evaluation board
• End launch, 2.92 mm RF connectors
• Through calibration path (depopulated)

The ADL8108-EVALZ is 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 ADL8108-EVALZ are populated with 2.92 mm, female coaxial connectors, and the corresponding RF traces have a 50 Ω characteristic impedance. The ADL8108-EVALZ is populated with components suitable for use over the entire −40°C to +85°C operating temperature range of the ADL8108. 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 to use the through calibration path. Refer to Table 1 and Figure 4 for the through calibration path performance.

Access the ADL8108-EVALZ ground path and VDD pin through the surface-mount technology (SMT) test point connectors, GND and VDD. A supplementary test point for VRBIAS is included for simple access on the RBIAS pin (see Figure 6 for the test point locations).

The RF traces on the ADL8108-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.

The power supply decoupling capacitors on the ADL8108-EVALZ represent the configuration used to characterize and qualify the device.

For full details on the ADL8108, see the ADL8108 data sheet, which must be consulted in conjunction with this user guide when using the ADL8108-EVALZ.