Multilayer substrate and antenna module

Abstract

The objective of this invention is to provide a multilayer substrate and antenna module with high reliability and excellent transmission characteristics. One embodiment of this technology comprises a multilayer substrate having a plurality of conductor layers and interlayer connections. The plurality of conductor layers includes: a line conductor layer having coplanar lines, and a pair of adjacent conductor layers adjacent to the line conductor layer. The interlayer connections include a plurality of columnar conductors connecting the plurality of conductor layers to each other. The multilayer substrate constructs a return current path in a manner that suppresses transmission losses caused by the return current flowing between the coplanar lines and the pair of adjacent conductor layers via the columnar conductors within the operating frequency band of the coplanar lines.