Wideband and high efficient aperture antenna with superstrate for 60 GHz indoor communication systems

TLDR: In this paper, the authors proposed a wideband, high efficient and high-gain aperture antenna with superstrate for 60 GHz communication, which is a promising candidate for fulfilling the future needs for very high bandwidth wireless connections.

Abstract: The 60 GHz millimeter wave (MMW) radio technology is a promising candidate for fulfilling the future needs for very high bandwidth wireless connections. It enables up to gigabit-scale connection speeds to be used in indoor WLAN networks or fixed wireless connections in metropolitan areas. Generally speaking, the more speed we need the more bandwidth we need. Transmission of several hundred megabits (or even several gigabit) per second requires very large bandwidth, which is available in the millimeter wave area. Large frequency range is allocated for unlicensed wireless telecommunications around 60 GHz (typically 59 – 66 GHz) all over the world, which makes the deployment of 60 GHz systems a lot smoother operation. In Europe the frequency ranges 62 – 63 GHz and 65 −66 GHz are reserved for wideband mobile networks (MBS, Mobile Broadband System), whereas 59 – 62 GHz range is reserved for unlicensed wideband wireless local area networks (WLAN); In the United States the frequency range 57 – 64 GHz is a generally unlicensed range; In Japan 59 – 66 GHz is reserved for wireless communications [1]. These new systems will need compact and high efficiency millimeter front-ends and antennas. For antennas, printed solutions are always demanding for the researchers because of its small size, weight and ease of integration with active components [2]. Conventional antenna arrays are used for high gain applications, but in these cases, arrays of large number of elements are required which induced an increase of the size of the antenna combined with a decrease of the efficiency [3],[4]. It has been reported that for high gain, a superstrate layer can be added at a particular height of 0.5 λ 0 above the ground plane [5]-[7]. This solution enables an improvement in gain of nearly 4 dB over a single parasitic patch at 12 GHz [5] and 5 dB at 10 GHz [6], but 9 dB at 60 GHz with an optimised superstrate size [7]. In this paper, the authors are proposing a wideband, high efficient and high-gain aperture antenna with superstrate for 60 GHz communication. It is known that adding a superstrate with a specific size will induce a significant effect on antenna gain and radiation patterns. The maximum measured gain of a single aperture antenna with superstrate is 13.1 dBi, which is higher than that of a classical 2 × 2 array. The measured gain of a single antenna with superstrate compared to the basic aperture antenna shows an increase of 8 dB at 60 GHz. This superstrate antenna gives an estimated efficiency of 79%. The measured 2:1 VSWR bandwidth is 15%, that covers the 60 GHz application band, which is one advantage of this antenna configuration compared to reference [7]. The radiation patterns are found to be broadside all over the frequency band with very low back radiation. Hence aperture antenna with superstrate is a good candidate for wideband, high efficient high gain application at 60 GHz.