The ADL7078-EVALZ is a 2-layer printed circuit board (PCB) fabricated
from 10 mil thick, Rogers 4350B, and copper clad.
The RFIN and RFOUT ports on the ADL7078-EVALZ are populated
with 2.9 mm, female coaxial connectors, and the corresponding RF
traces have a 50 Ω characteristic impedance. The ADL7078-EVALZ
is populated with components suitable for use over the entire −40°C
to +85°C operating temperature range.
To calibrate board trace losses, a through calibration path, THRUCAL,
is provided between the J1 and J2 connectors. J1 and J2
must be populated with RF connectors to use the through calibration
path. For the through calibration path performance, see Table 1
and Figure 4 in the user guide.
Access the ADL7078-EVALZ ground path and the 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 (for the test point locations, see
Figure 6) in the user guide.
The RF traces on the ADL7078-EVALZ are 50 Ω, grounded, coplanar
waveguide. The package ground leads and the exposed pads
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 ADL7078-EVALZ
represent the configuration used to characterize and qualify the
device.
