Millimeter Wave Antennas

This chapter presents the Integrated Lens Antenna (ILA) technology as it evolved since its introduction aiming to respond to the needs of emerging applications such as high-data-rate communication, intelligent transport, and mm-wave imaging. The topics covered include the ILA design concepts as well as the electromagnetic phenomena intrinsic to dielectric lenses that may affect ILA performance. The aspects of the ILA technology related to selection of the primary feeds, lens materials, and fabrication methods are also revised. A few practical examples are provided to illustrate the current and future trends of this technology.

In this paper, we propose a ball grid array (BGA) module with an integrated 3-D-printed plastic lens antenna for application in a dedicated 130 GHz OOK transceiver that targets the area of 5G backhaul/fronthaul systems. The main design goal was the full integration of a small footprint antenna with an energy-efficient transceiver. The antenna system must be compact and cost effective while delivering an approximately 30 dBi gain in the working band, defined as 120 to 140 GHz. Accordingly, a 2 × 2 array of aperture-coupled patch antennas was designed in the 7 × 7 × 0.362 mm 3 BGA module as the feed antenna of the lens. This achieved a 7.8 dBi realized gain, broadside polarization purity above 20 dB, and over 55% total efficiency from 110 to 140 GHz (20% bandwidth). A plastic elliptical lens 40 mm in diameter and 42.3 mm in height was placed on top of the BGA module. The antenna achieved a return loss better than −10 dB and a 28 dBi realized gain from 114 to 140 GHz. Finally, active measurements demonstrated a >12 Gbps Tx/Rx link at 5 m with bit error rate (BER) < 10 −6 at 1.6 pJ/b/m. These results pave the way for future cost-effective, energy-efficient, high-data rate backhaul/fronthaul systems for 5G communications. Index Terms— 3-D printing, 5G, backhaul/fronthaul links, ball grid array (BGA), dielectric lens, millimeter-wave (mmw) antennas, organic module.

Many wireless communication applications such as satellite communications use circularly polarized (CP) signals, with the requirement for easy switching of the polarization sense between uplink and downlink. Specifically, in satellite communications , the trend is also to move to higher frequencies and integrate the receiving and transmitting antennas in one dual-band terminal. However, these simultaneous demands make the design and fabrication of the composing parts very challenging. We propose, here, a dual-band dual-linear polarization (LP)-to-CP converter that works in the transmission mode. The working principle of this polarizer is explained through an example for Ka-band satellite communications at 19.7–20.2 and 29.5–30 GHz. The LP-to-CP converter is a single panel composed of identical unit cells with a thickness of only 1.05 mm and a size of 5.3 mm × 5.3 mm. Due to its operation in the transmission mode, the polarizer can be combined with a simple dual-band dual-LP antenna to obtain the desired dual-band dual-CP single antenna. However, the unique property of this polarizer is yet the fact that it converts a given LP wave, e.g., x-polarization, to orthogonal CP waves at the two nonadjacent frequency bands, e.g., left-handed CP at lower band and right-handed CP at higher band. The polarizer is tested both with 20 and 30 GHz LP rectangular horns to illuminate a dual-band transmit array (TA) to obtain wide-angle steering of CP beams. The performance of the polarizer and its association with the TA is evaluated through simulation and measurements. We also present design guidelines for this type of polarizer. Index Terms— Antenna–filter–antenna, circular polarization (CP), dual-band antennas, frequency selective surfaces, periodic structures, polarization conversion.