ADH8412S

• 4-layer, Rogers 4350B and Isola 370HR evaluation board
• End launch, 3.5 mm RF connectors
• Through calibration path (depopulated)

The EV1HMC8412LP2F consists of a 4-layer printed circuit board (PCB) fabricated from 10 mil thick, Rogers 4350B and Isola 370HR, copper clad, forming a nominal thickness of 62 mils. The RFIN and RFOUT ports on the EV1HMC8412LP2F are populated with 3.5 mm, female coaxial connectors, and the corresponding RF traces have a 50 Ω characteristic impedance. The EV1HMC8412LP2F is populated with components suitable for use over the entire −40°C to +85°C operating temperature range of the HMC8412. To calibrate board trace losses, a through calibration path is provided between the J1 and J2 connectors. J1 and J2 must be populated with RF connectors to use the through calibration path. Refer to Table 1 and Figure 3 for the through calibration path performance. Access the EV1HMC8412LP2F ground path and VDD pin through the surface-mount technology (SMT) test point connectors, GND and VDD. A supplementary test point for VBIAS is included for simple access on the RBIAS pin (see Figure 5 for the test point assembly).

The RF traces on the EV1HMC8412LP2F are 50 Ω, grounded, coplanar waveguide. The package ground leads and the exposed pad connect directly to the ground plane. Multiple vias connect the top and bottom ground planes with particular focus on the area directly beneath the ground paddle to provide adequate electrical conduction and thermal conduction to the heat sink.

The power supply decoupling capacitors on the EV1HMC8412LP2F represent the configuration used to characterize and qualify the device. It is possible to reduce the number of capacitors, but this reduction varies from system to system. It is recommended to first remove or combine the largest capacitors that are farthest from the HMC8412 when reducing the number of capacitors. 

EQUIPMENT NEEDED

• RF signal generator
• RF spectrum analyzer
• RF network analyzer
• 5 V, 100 mA power supply