60-Ghz circularly polarized u-slot patch antenna array on LTCC

Abstract

This communication presents a 60-GHz wideband circularly polarized (CP) U-slot patch antenna array of 4× 4 elements on low temperature cofired ceramic (LTCC). A CP U-slot patch antenna is used as the array element to enhance the impedance bandwidth and a stripline sequential rotation feeding scheme is applied to achieve wide axial ratio (AR) bandwidth. Meanwhile, a grounded coplanar waveguide (GCPW) to stripline transition is designed for probe station measurement. The fabricated antenna array has a dimension of 14× 16× 1.1 mm}3. The simulated and measured impedance bandwidths, AR bandwidths, and radiation patterns are investigated and compared. Measured results show that the proposed antenna array has a wide impedance bandwidth from 50.5 GHz to 67 GHz for vert S} -11} vert < -10∼ dB}, and a wide AR bandwidth from 54 GHz to 65.5 GHz for AR}< 3∼ dB}. In addition, it exhibits a peak gain of 16 dBi and a beam-shaped pattern with 3-dB beam width of 20 circ. Moreover, its AR keeps below 3 dB within the 3-dB beam width. © 1963-2012 IEEE.