Data Sheet HMC349AMS8G
Rev. C | Page 9 of 10
APPLICATIONS INFORMATION
EVALUATION BOARD
The HMC349AMS8G uses a 4-layer evaluation board. The
copper thickness is 0.5 oz (0.7 mil) on each layer. The top
dielectric material is 10 mil Rogers RO4350, which offers good
high frequency performance, whereas the middle and bottom
dielectric materials are FR-4 type materials to achieve an overall
board thickness of 62 mil. 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 RF transmission lines are designed
using a coplanar waveguide (CPWG) model with a width of
16 mil and ground spacing of 13 mil to have a characteristic
impedance of 50 Ω. For good RF and thermal grounding, as
many plated through vias as possible are arranged around
transmission lines and under the exposed pad of the package.
Figure 18 shows the top view of populated HMC349AMS8G
evaluation board, available from Analog Devices, Inc., upon
request (see the Ordering Guide). The package ground pins are
connected directly to the ground plane which is connected to
the GND test points (TP1 and TP5). A single power supply port
is connected to the dc test point labeled VDD (TP2). An unpop-
ulated bypass capacitor position is available to filter high frequency
noise on the supply trace. Two control ports are connected to
the CTRL and EN test points (TP3 and TP4). The RF ports are
connected to the RFC, RF1, and RF2 connectors (J1, J3, and J2)
that are PC mount SMA RF connectors. Additionally, 100 pF dc
blocking capacitors (C1, C2, C3) are used on RF transmission
lines. A through transmission line that connects unpopulated
RF connectors (J4 and J5) is also available to measure and remove
the loss of the PCB.
Figure 18. Populated Evaluation Board
Figure 19 and Table 5 are the evaluation board schematic and
bill of materials, respectively.
1 VDD
CTRL
EN
2
3
4
8
7
6
5
RFC
RF2
GND
RF1
GND
U1
HMC349AMS8G
TP2
TP3
VDD
CTRL
EN
TP4
C4
DEPOP
C1
100pF
RFC
RF2
RF1
J1
C2
100pF
C3
100pF
J4
DEPOP
J5
DEPOP
J2
J3
GND
TP1
GND
TP5
C5
DEPOP
C6
DEPOP
THRU
15025-018
Figure 19. Evaluation Board Schematic
Table 5. Bill of Materials, Evaluation Board Components
Component Description
J1, J2, J3 PC mount SMA connectors
J4, J5 Unpopulated PC mount SMA connectors
TP1 to TP5 Through hole mount test points
C1, C2, C3 100 pF capacitors, 0402 package
C4, C5, C6 Unpopulated capacitors, 0402 package
U1 HMC349AMS8G SPDT switch
PCB 107660-1 evaluation PCB
