A Low-Cost and High-Gain 60-GHz Differential Phased Array Antenna in PCB Process

A broadband, low-cost, high-gain, multilayer differential antenna without air cavity is proposed for the 60-GHz phased array system. By using the standard low-cost printed circuit board process, a 60-GHz phased array antenna element and a 16-element phased array antenna prototype are implemented. To improve the bandwidth and antenna gain, a superstrate and a float rectangular ring are designed. The float ring can enhance the antenna vertical radiation, suppressing the antenna horizontal radiation and reducing the mutual coupling. Without any embedded air cavity, the proposed antenna is robust against the process variation, which is verified in the measurement. For the antenna element, the measured results demonstrate a peak gain of 8.9 dBi and a 10-dB return-loss bandwidth of more than 12 GHz, and the simulated radiation efficiency is above 90% at 60-GHz band. For the phased array antenna, two beam-fixed (0° and 30°) array antennas are tested to verify the beam scanning performance, which achieve gains of 16.3 and 13.6 dBi, respectively.