ADRF5025 Data Sheet
Rev. A | Page 10 of 13
APPLICATIONS INFORMATION
EVALUATION BOARD
The ADRF5025-EVA L Z is a 4-layer evaluation board. The outer
copper (Cu) layers are 0.5 oz (0.7 mil) plated to 1.5 oz (2.2 mil)
and are separated by dielectric materials. Figure 17 shows the
evaluation board stackup.
0.5oz Cu (0.7mil)
RO4003
0.5oz Cu (0.7mil)
1.5oz Cu (2.2mil)
1.5oz Cu (2.2mil)
W = 14mil
G = 7mil
T = 2.2mil
H = 8mil
1.5oz Cu (2.2mil)
1.5oz Cu (2.2mil)
TOTAL THICKNESS
–62mil
16533-017
Figure 17. Evaluation Board (Cross Section View)
All RF and dc traces are routed on the top copper layer, whereas
the inner and bottom layers are grounded planes that provide
a solid ground for the RF transmission lines. The top dielectric
material is 8 mil Rogers RO4003, offering optimal high
frequency performance. The middle and bottom dielectric
materials provide mechanical strength. The overall board
thickness is 62 mil, which allows 2.4 mm RF launchers to
be connected at the board edges.
16533-018
WITHOUT
IMPEDANCE
MATCH
WITH
IMPEDANCE
MATCH
Figure 18. Evaluation Board Layout, Top View
The RF transmission lines were designed using a coplanar
waveguide (CPWG) model, with trace width of 14 mil and
ground clearance of 7 mil to have a characteristic impedance of
50 Ω. For optimal RF and thermal grounding, as many plated
through vias as possible are arranged around transmission lines
and under the exposed pad of the package.
The ADRF5025-EVA L Z has two layouts implemented; with and
without impedance matching. By default, the impedance matched
circuit is populated. For more details on the impedance matched
circuit, refer to Impedance Matching in the Probe Matrix Board
section.
THRU CAL can be used to calibrate out the board loss effects
from the ADRF5025-EVAL Z evaluation board measurements to
determine the device performance at the pins of the IC. Figure 19
shows the typical board loss for the ADRF5025-EVA L Z
evaluation board at room temperature, the embedded insertion
loss, and the de-embedded insertion loss for ADRF5025.
–7
–6
–5
–4
–3
–2
–1
0
0 5
10
15
20
25
30
35
40
45
50
INSERTION LOSS (dB)
FREQUENCY (GHz)
THRU LOSS
EMBEDDED INSERTION LOSS
DEEMBEDDED INSERTION LOSS
16533-021
Figure 19. Insertion Loss vs. Frequency
Figure 20 shows the actual ADRF5025-EVA L Z with its
component placement.
Two power supply ports are connected to the VDD and VSS
test points, TP7 and TP5 (or TP3 and TP1 if using without the
impedance match circuit), and the ground reference is
connected to the GND test point, TP4 or TP8. On the supply
traces, VDD and VSS, a 100 pF bypass capacitor filters high
frequency noise. Additionally, unpopulated components
positions are available for applying extra bypass capacitors.
A control port is connected to the CTRL test point, TP6 (or
TP2 for without the impedance match circuit). There are
provisions for the resistor capacitor (RC) filter to eliminate dc-
coupled noise, if needed, by the application. The resistor can
also improve the isolation between the RF and the control signal.
The RF input and output ports (RFC, RF1, and RF2) are
connected through 50 Ω transmission lines to the 2.4 mm
RF launchers, J10, J9, and J8 (or J2, J3, and J1 for the without
impedance match circuit), respectively. These high frequency
RF launchers are by contact and are not soldered to the board.
A THRU cal line connects the unpopulated J6 and J7 launchers
(or J4 and J5 for without the impedance match circuit). This
transmission line is used to estimate the loss due to the PCB
over the environmental conditions being evaluated.
The schematic of the ADRF5025-E VA L Z evaluation board
is shown in Figure 21.
