Several gigahertz of bandwidth are now available in the 60-GHz band for short-range communications applications. For antennas, this trend has reinforced the move from discrete designs to integrated on-chip or in-package solutions. For designs that are closer to bringing low-cost, highly integrated 60-GHz solutions to fruition, multilayer, low-temperature co-fired ceramic (LTCC) technology has been used successfully. At the National University of Singapore, for example, a 60-GHz wideband, circularly polarized helical antenna array of 4x4 elements has been designed and fabricated using LTCC technology. This antenna is the work of Changrong Liu, Yong-Xin Guo, Xiaoyue Bao, and Shao-Qiu Xiao.
LTCC has been heralded for its light weight, compactness, and high performance. In this design, the flexible via-hole distribution is leveraged to realize a helical antenna array with good circular polarization performance. For probe-station measurements, grounded coplanar waveguide (GCPW) to stripline is used. The fabricated antenna array, which measures 12 x 10 x 2 mm, shows a measured impedance bandwidth of 52.5 to 65.5 GHz for | S11 | below −10 dB. See “60-GHz LTCC Integrated Circularly Polarized Helical Antenna Array,” IEEE Transactions On Antennas And Propagation, March 2012, p. 1329.
