US Patent 7710323 Flat mobile antenna system

An antenna system comprising a first multi-layer Printed Circuit Board having multiple antenna elements disposed thereon, at least a second multi-layer PCB, which is mounted below the first multi-layer PCB, and which comprises electronic components for processing Radio Frequency signals received by the antenna elements; and multiple RF transitions, which are mounted between the first and second multi-layer PCBs and are operative to transfer the RF signals from the first multi-layer PCB for processing by the electronic components in the second multi-layer PCB.