Data Sheet

ADRF5044

Rev. A | Page 13 of 14

PROBE MATRIX BOARD

The probe matrix board is a 4-layer board that uses a 12 mil

Rogers RO4003 as the top dielectric material. The external

copper layer is 0.7 mil, and the internal copper layers are

1.4 mil. The RF transmission lines were designed using a

CPWG model, with a 16 mil width and a ground spacing of

6 mil, to have a characteristic impedance of 50 Ω.

Figure 26 shows the cross sectional view of the probe matrix

board, and Figure 27 shows the top view of the probe matrix

board. Measurements were made using 535 μm GSG probes at

close proximity to the RFx pins. Unlike the ADRF5044-EVALZ,

probing reduces reflections caused by mismatch arising from

connectors, cables, and board layout, resulting in a more

accurate measurement of the performance of the ADRF5044.

RO4003

1oz Cu (1.4mil)

1oz Cu (1.4mil)

0.5oz Cu (0.7mil)

0.5oz Cu (0.7mil)

0.5oz Cu (0.7mil)

0.5oz Cu (0.7mil)

FR4

FR4

W = 16mil

G = 6mil

T = 0.7mil

H = 12mil

Figure 26. Probe Matrix Board (Cross Sectional View)

Figure 27. Probe Board Layout (Top View)

RF traces for a through reflect line (TRL) calibration are

designed on the board itself. A nonzero line length

compensates for board loss at calibration. The actual board

duplicates the same layout in matrix form to assemble multiple

devices at once. Insertion loss and input and output return

losses were measured on this probe matrix board. Isolation

performance measured on the probe matrix board is limited

due to signal coupling between the RF probes that are in close

proximity. Therefore, RF port to port isolation was measured

on the ADRF5044-EVALZ.