Data Sheet

HMC1055

Rev. A | Page 9 of 10

APPLICATIONS INFORMATION

EVALUATION PRINTED CIRCUIT BOARD (PCB)

The HMC1055 evaluation board is constructed of a 4-layer

material with a copper thickness of 0.7 mil on each layer. Every

copper layer is separated with a dielectric material. The top

dielectric material is 10 mil RO4350. The middle and bottom

dielectric materials are FR-4, used for mechanical strength and

overall board thickness of approximately 62 mil, which allows

SMA connectors to be slipped in at the board edges.

All RF and dc traces are routed on the top copper layer. The RF

transmission lines are designed using a coplanar waveguide

(CPWG) model, with a width of 16 mil, spacing of 13 mil, and

dielectric thickness of 10 mil, to have a characteristic imped-

ance of 50 Ω. The inner and bottom layers are grounded planes

to provide a solid ground for the RF transmission lines. For

optimal electrical and thermal performance, as many vias as

possible are arranged around the transmission lines and under

the package exposed pad. The evaluation board layout shown in

Figure 14 serves as a recommendation for optimal and stable

performance, as well as for improvement of thermal efficiency.

The package ground pins are connected directly to the ground

plane. The supply voltage and control voltage must be con-

nected to the dc pins, J3 and J4, respectively, of the evaluation

board. One decoupling capacitor is populated on the supply

trace to filter high frequency noise.

The RF input and output ports (RF1 and RF2) are connected

through 50 Ω transmission lines to the SMA connectors, J1

and J2, respectively. The RF1 and RF2 ports are ac-coupled

with capacitors of an appropriate value to ensure broadband

performance. A thru calibration line connects J5 and J6; this

transmission line is used to estimate the loss of the PCB over

the environmental conditions being evaluated.

EVALUATION BOARD SCHEMATIC AND ARTWORK

Figure 13. Evaluation Board Schematic

Table 5. List of Materials for EVAL01-HMC1055LP2C

Item

Description

J1, J2

PCB mount, SMA, RF connector

J3, J4

DC pin

C1

1 nF capacitor, 0402 package

C2, C3

330 pF capacitor, 0402 package

U1

HMC1055 SPST switch

PCB

600-00215-00-1 evaluation PCB

Figure 14. Evaluation Board Layout—Top View

J6

DEPOP

1

J5

DEPOP

1

C4

330pF

DEPOP

C5

330pF

DEPOP

U1

HMC1055

J2

RF2

1

C3

330pF

J4

J3

J1

RF1

1

C2

330pF

C1

1nF