Design and Comparison of 24GHz Patch Antennas on Glass Substrates for CompactWireless Sensor Nodes

摘要

Three patch antennas suitable for integration and operation in a compact 24 GHz wireless sensor node with radar and communication functions are designed, characterized, and compared. The antennas are manufactured on a low loss glass wafer using thin film (BCB/Cu) wafer level processing (WLP) technologies. This process is well suited for 3D stacking. The antennas are fed through a microstrip line underneath a ground plane coupling into the patch resonator through a slot aperture. Linear polarization (LP), dual mode (DM) operation, and circular polarization (CP) are achieved through the layout of the slot aperture and rectangular patch dimensions. Antenna gain values of ～5.5 dBi are obtained in addition to the 10 dB impedance bandwidths of 900MHz and 1.3GHz as well as 500MHz CP bandwidth with a 3 dB axial ratio for the LP, DM, and CP patch antennas, respectively.