ADRF5250 Data Sheet
Rev. 0 | Page 12 of 15
APPLICATIONS INFORMATION
EVALUATION BOARD
Figure 18 and Figure 19 show the top and cross sectional views
of the evaluation board, which uses 4-layer construction with a
copper thickness of 0.5 oz (0.7 mil) and dielectric materials
between each copper layer.
Figure 18. Evaluation Board Layout Top View
0.5oz Cu (0. 7m i l )
0.5oz Cu (0. 7m i l )
0.5oz Cu (0. 7m i l )
0.5oz Cu (0. 7m i l )
10mil ROG E RS 4350B
10mil ROG E RS 4350B
8mil ROG E RS 4450F
0.5oz Cu (0. 7m i l )
0.5oz Cu (0. 7m i l ) 0.5oz Cu (0. 7m i l )
TO TAL THICKNESS
~30mil
W = 8m i l G = 10m il
15506-118
Figure 19. Evaluation Board Cross Sectional View
All RF traces are routed on Layer 2; the V1, V3, and VSS dc
traces are routed on Layer 3; the V2 and VDD dc traces are
routed on the top layer; and the other remaining layers are
grounded planes that provide a solid ground for RF transmission
lines. The top and bottom dielectric material are Rogers 4350B,
offering low loss performance. The middle dielectric material is
Rogers 4450F and is used to achieve an overall board thickness
of 30 mil. The RF transmission lines were designed using a
coplanar waveguide (CPWG) model with a width of 8 mil and
ground spacing of 10 mil for a characteristic impedance of 50 Ω.
For optimal RF and thermal grounding, as many plated through
vias as possible are arranged around the transmission lines and
under the exposed pad of the package.
Figure 20 shows the actual ADRF5250 evaluation board with
component placement. Two power supply ports are connected
to the VDD and VSS test points, TP3 and TP5, and the ground
reference is connected to the GND test point, TP6. On the digital
control and VDD supply traces, bypass capacitors are used.
Figure 20. ADRF5250-EVALZ Evaluation Board
Three control ports are connected to the V1, V2, and V3 test
points, TP1, TP2, and TP4, respectively. On each control trace,
a resistor position is available to improve the isolation between
the RF and control signals. The RF ports are connected to the
RFC, RF1, RF2, RF3, RF4, and RF5 connectors (J6, J8, J7, J5, J2,
and J1), which are end launch jack SMA RF connectors. A
through transmission line that connects unpopulated RF
connectors (J3 and J4) is also available to measure the loss of
the PCB. Figure 22 and Table 6 show the evaluation board
schematic and bill of materials, respectively.
The evaluation board shown in Figure 20 is available for order
from the Analog Devices, Inc., website at www.analog.com.