Antenna design and characterization for a 61 GHz transceiver in eWLB package

In this article, we present the feasibility of an antenna concept at the ISM (Industrial, Scientific and Medical) band for a two-channel 61 GHz transceiver in embedded wafer level ball grid array (eWLB) technology. The eWLB is an innovative package solution for high-frequency and high-performance applications. We present both simulation and measurement results of antennas which are integrated in the thin-film redistribution layer (RDL) of an eWLB package. Two λ/2-dipole antennas are used for transmitter (TX) and receiver (RX). The package including the antennas is soldered on a RF board in order to measure radiation pattern and scattering parameters (S-parameters). The measured isolation between two antennas is -25 dB and they have a return loss of -26 dB. The observed gain of a single antenna is about 8 dBi and the antenna input impedance bandwidth is 5 GHz. We investigate the impact of package size on the antenna radiation pattern. We present the analysis of the antenna-package interactions and determine the optimum distance of the antennas in package to the reflector on board.