Millimetre Wave Antenna Design for 5G Applications

Abstract

Due to the greater demand in the field of wireless communication, mmWave technology is preferred for various advantages, such as large operating bandwidth, higher data rate, higher operating frequency, and shorter wavelength. This technology has less penetration and propagation loss as compared to the microwave frequency bands. In general, antenna plays a very important role in terms of receiver sensitivity, link budget analysis, transceiver design, and other digital modulation schemes. The spectrum allocated for the mmWave is from 30 GHz to 300 GHz, and the required spectrum for 5G applications is from 20 GHz to 90 GHz. Many of the mmWave antenna research is focussed on developing the antenna on chip using CMOS technology and mmWave phased-array designs. The other research efforts focused on finding the effects of cellular phones, reducing the cost, and increasing the gain of the antenna. To reduce the signal loss in mmWave propagation, phased-array antennas are preferred due to their higher gain. The radiation pattern of the phased array can also be adjusted to change the maximum beam direction. The key parameters, like steering angle, resolution, side-lobe level size of the array, and polarization, are considered in designing the phased array. In handheld devices, the number of antennas is increased to support high data rate and reliability. This increases the overall dimensions of the devices. Hence, the frequency reconfigurable method and antenna in package help reduce the space constraint problem. To support both long-range and short-range communications, 4G and 5G applications need to be integrated in a single antenna design. Hence, MIMO method and dual-function approach of the antenna act as the solutions for integrating the antenna. The isolation techniques, diversity gain, envelope correlation coefficient also need to be analyzed for the MIMO antennas. The next challenge in the fabrication of mmWave antenna is the tolerance of the dielectric material and its thickness in higher frequency. The loss tangent value of the material also changes and is unpredictable at high frequency. The properties of SMD components fabricated in the PCB change after 6 GHz. Since the wavelength is very short, the effects of skin depth, losses due to conductors, and dielectric surface roughness need to be considered.