Layer Construction
High-frequency layer arrangement determines the signal loss and signal integrity for circuits operating between 110 GHz and 170 GHz. Designing a d-band pcb stackup involves selecting thin dielectrics and low-profile copper foils to minimize skin effect losses. These layers must be balanced to prevent warping during the high-temperature lamination processes required for advanced materials.
The distance between the signal layer and the ground plane is often less than 100 microns to maintain impedance control.
Material Selection
Dielectric properties are the primary factor in the performance of the high-speed signal paths. A d-band pcb stackup typically uses polytetrafluoroethylene or liquid crystal polymer to ensure a low dissipation factor. These materials provide the stability required to prevent frequency shifts as the temperature of the device changes.
Using a hybrid construction can reduce costs by placing high-frequency materials only where they are needed for signal routing.
Thermal Management
Heat dissipation becomes more difficult when using the thin substrates required for millimeter-wave designs. The d-band pcb stackup must include thermal vias or metal cores to move heat away from active components. Because the dielectric materials are often poor thermal conductors, the copper planes are used to distribute heat across the board.
This thermal strategy is necessary to prevent component failure in high-power radar or communication systems.
