Package Integration
Packaging configurations integrate radiating elements directly with the transceiver chip on a single substrate to reduce transmission losses at millimeter-wave frequencies. Modern high frequency modules use antenna-in-package structures to eliminate the need for long rf coaxial routing on the system board. This integration reduces signal degradation by placing the antenna within millimeters of the active circuitry.
Electromagnetic Shielding
Shielding design in these highly integrated packages prevents unwanted radiation from interfering with nearby analog or digital circuits. Designers utilize selective plating and metal cages to isolate the transceiver from the radiating patches. In addition, the placement of ground vias around the antenna structure helps direct the signal outward rather than allowing it to leak into the inner substrate layers.
This boundary requires careful layout verification because any misplaced via can alter the radiation pattern and degrade signal performance. This careful routing also ensures that the thermal dissipation from the transceiver does not warp the radiating structure.
Assembly Tolerance
Precision placement of the package components on the motherboard during final assembly prevents impedance mismatches. Solder sphere size and reflow temperature must be carefully controlled to maintain the designed standoff height. Variation in height changes the capacitance between the package antenna and the system ground plane.
