Design of 28 GHz 4x4 RF Beamforming Array for 5G Radio Front-Ends

Current state of wireless infrastructure sees mass migration to higher frequencies as much of the already used spectrum is insufficient in supporting the influx of numerous users and various data intensive mobile applications. Data rates are projected to increase by an order of magnitude and harnessing the necessary bandwidth below 6 GHz is not feasible. A move to higher frequencies sees not only increased fractional bandwidth, but also significantly enhanced antenna apertures as a result of beamforming capabilities. Due to device level complications with frequencies nearing the unit gain frequency of transistor technology, high output power is seldom found, and in conjunction with severe path loss, communication links cannot be established without the usage of antenna arrays. Phased array systems offer significant upside to the traditional array implementation as it permits reconfigurable directive communication. However, Ka-Band phased arrays still struggle to arrive at a reasonable tradeoff between design complexity, cost and performance. With a divide between both organic and printed circuit board (PCB) based approaches to the development of an antenna-in-package (AiP), this thesis sides with the latter. An antenna-on-PCB variant of the AiP is developed, which implements both commercially available RF laminates and RFIC front end modules to produce a 28 GHz 4x4 RF beamforming phased array that is found to exhibit extremely low loss (-0.66 dB), adequate scan volume (+/- 45 degrees, in E and H planes) and large bandwidth (3 GHz) for a single layer, non-isolated patch antenna design. Unit cell, infinite array analysis is emphasized and lattice resizing is leveraged to obtain desired scan performance, while significantly reducing design complexity via the absence of intricate isolation enhancement techniques. In an effort to aid in application based design, the AiP is extended to application of linearization where it is found that the inclusion of dummy elements along the perimeter of the package not only serve as element pattern enhancement, but also provide reliable means of output signal capture. Negating the traditional transmitter observation receiver (TOR) architecture, the AiP design as a TOR for millimeter-wave communication proves optimistic in the quest for maximum system efficiency

Cost-effective high-performance air-filled SIW antenna array for the global 5G 26 GHz and 28 GHz bands

A cost-effective, compact, and high-performance antenna element for beamforming applications in all fifth-generation (5G) New Radio bands in the [24.25-29.5] GHz spectrum is proposed in this letter. The novel antenna topology adopts a square patch, an edge-plated air-filled cavity, and an hourglass-shaped aperture-coupled feed to achieve a very high efficiency over a wide frequency band in a compact footprint (0.48 lambda(0) x 0.48 lambda(0)). Its compliance with standard printed circuit board (PCB) fabrication technology, without complex multilayer PCB stack, ensures low-cost fabrication. The antenna feedplane offers a platform for compact integration of active electronic circuitry. Two different modular 1 x 4 antenna arrays were realized to demonstrate its suitability for broadband multiantenna systems. Measurements of the fabricated antenna element and the antenna array prototypes revealed a-10 dB impedance bandwidth of 7.15 GHz (26.8%) and 8.2 GHz (30.83%), respectively. The stand-alone antenna features a stable peak gain of 7.4 +/- 0.6 dBi in the [24.25-29.5] GHz band and a measured total efficiency of at least 85%. The 1 x 4 array provides a peak gain of 10.1 +/- 0.7 dBi and enables grating-lobe-free beamsteering from -50 degrees to 50 degrees

IC-Antenna Co-Integration for Efficient and Scalable Millimeter-Wave Antenna Interfaces

Millimeter-wave (mm-wave) technology promises high speed, high system capacity and low latency interconnects with reduced cost. Applications like high data-rate wireless links, next generation automotive sensors and security body scanners highly depend on mm-wave technology innovations. As operating frequency moves to higher mm-wave bands, shrinking antenna dimensions enable co-integration of IC and antenna. Limited transistor output power at mm-wave requires multi-element arrays to satisfy communication and radar link budgets. This dissertation presents a wafer-scale compatible IC-antenna co-integration for efficient and scalable mm-wave antenna interfaces. The proposed IC-antenna co-integration approach is demonstrated through single antenna transmitters, a concurrent dual-polarization receiver front-end and polarization-duplex transmitter/receiver front-end. Chapter 2 discusses the challenge of mm-wave IC-antenna interfaces with prior art including antenna-in-package (AiP) and on-chip antennas. The 60 GHz efficient, scalable and wafer-scale compatible IC-antenna co-integration approach is presented demonstrating wide bandwidth and large efficiency which are comparable to system-level AiP techniques at a lower cost and fabrication complexity. Chapter 3 extends the proposed approach to a concurrent 60 GHz dual-polarization receiver front-end for short-range imaging/communication applications and polarization diversity based MIMO links. Active cancellation between orthogonal polarizations is adopted to achieve ∼ 30 dB cross-polarization leakage cancellation and concurrent dual-pol reception. Chapter 4 presents a 60 GHz simultaneous transmit and receive front-end to achieve efficient polarization-duplex operation based on dual-polarization IC-antenna co-integration. Transmitter leakage is suppressed at receiver input and output by intrinsic antenna isolation and a feed-forward passive canceller. Total average self-interference cancellation >40 dB is achieved for 1.07 GHz RF bandwidth at 60 GHz in the presence of a reflector