A 37-40 GHz Dual-Polarized 16-Element Phased-Array Antenna with Near-Field Probes

With the development of fifth-generation (5G) communication networks, in order to meet the growing demand for high-speed and low-latency wireless communication services, channel capacity has become the main driving force for choosing millimeter wave (mm-wave) over over-crowded sub-6 GHz frequency bands. Recently, beamforming phased array attracts significant research efforts as it is a promising solution and unique in its ability to overcome the high path-loss at high frequency, provide fast beam steering and deliver better user-ends experience. However, to alleviate the issues that associated with beamforming phased array, such as imbalance between array elements and non-linearity caused by power-amplifiers (PAs) in beamforming channels, far-field (FF) based array calibration and digital pre-distortion (DPD) need to be performed, which is not practical in real world scenario. This thesis presents a low-cost 16-element dual-polarized mm-wave antenna-on-printed circuit board (PCB) transmitter RF beamforming array with embedded near-field probes (NFPs) at 37-40 GHz. The elements are orthogonal, proximity-coupled feed dual-polarized patch antenna with a spacing of 0.5λ within 2x2 subarray and 0.6λ between 2x2 subarray at 38.5 GHz, resulting in maximum 17.7 dB gain with a scan angle of +/-50◦, +/-20◦ in azimuth and +/-20◦, +/-50◦ in elevation for vertical polarization and horizontal polarization, respectively. Without affecting phased array performance, the NFPs achieve flat and comparable coupling magnitude and group delay to the closet RF chain for both polarizations, across operating frequency range. This ensures the quality of received output signal from phased array to implement array calibration and DPD. The configuration of embedded NFPs maintains the scalability of phased array and eliminate the needs of impractical FF reference probe for array calibration and DPD

CMOS Front-End Circuits in 45-nm SOI Suitable for Modular Phased-Array 60-GHz Radios

Next Fifth-generation (5G) wireless technologies enabling ultra-wideband spectrum availability and increased system capacity can achieve multi-gigabit/s (Gbps) data rates suitable for ultra-high-speed internet access around the 60-GHz band (i.e., Wi-Gig Technology). This mm-wave band is unlicensed and experiences high propagation power losses. Therefore, it is suitable for short-range communications and requires antenna arrays to satisfy the link budget requirements. Half-duplex reconfigurable phased-array transceivers require wideband, low-cost, highly integrated front-end circuits such as bilateral RF switches, low-noise/power amplifiers, passive RF splitters/combiners, and phase shifters implemented in deep sub-micron CMOS. In this dissertation, analysis, design, and verification of essential CMOS front-end components are covered and fabricated in GlobalFoundries 45-nm RF-SOI CMOS technology. Firstly, a fully-differential, single-pole, single-throw (SPST) switch capable of high isolation in broadband CMOS transceivers is described. The SPST switch realizes better than 50-dB isolation (ISO) across DC to 43 GHz while maintaining an insertion loss (IL) below 3 dB. Measured RF input power for 1-dB compression (IP1dB) of the IL is +19.6 dBm, and the measured input third-order intercept point (IIP3) is +30.4 dBm (both assuming differential inputs at 20 GHz). The prototype has an active area of 0.0058 mm^2. Secondly, a single-pole double-throw (SPDT) switch is implemented using the SPST concept by using a balun to convert the shared differential path to a single-ended antenna port. The SPDT simulations predict less than 3.5-dB IL and greater than 40-dB ISO across 55 to 65 GHz frequency band. An IP1dB of +21 dBm is expected from large-signal simulations. The prototype has an active area of 0.117 mm^2. Thirdly, a fully-differential switched-LC topology adopted with slow-wave artificial transmission line concept, and phase inversion network is described for a 360-degree phase shift range with 11.25-degree phase resolution. The average IL of the complete phase shifter is 5.3 dB with less than 1-dB rms IL error. Furthermore, the IP1dB of the phase shifter is +16 dBm. The prototype has an active area of 0.245 mm^2. Lastly, a fully-differential, 2-stage, common-source (CS) low-noise amplifier (LNA) is developed with wideband matching from 57.8 GHz to 67 GHz, a maximum simulated forward power gain of 20.8 dB, and a minimum noise figure of 3.07 dB. The LNA consumes 21 mW and predicts an OP1dB of 4.8 dBm from the 1-V supply. The LNA consumes an active area of 0.028 mm^2

Agile intelligent antenna system for industry 4.0 and beyond

The next-generation industrial paradigms such as Industry 4.0 and beyond require ultra-high reliability, extremely low latency, high throughput, and fine-grain spatial differentiation for wireless communication, sensing, and control systems. Traditional industrial wired networks suffer from impediments such as expensive installation and maintenance costs, wear and tear, reduced flexibility, and restricted mobility in dynamic industrial environments. Moreover, the conventional sub-6 GHz industrial, scientific, and medical (ISM) wireless bands such as 2.4 and 5 GHz are not able to fully meet the requirements of high bandwidth, high data rate, and low latency for emerging industrial wireless applications. To overcome the aforementioned challenges, the utilization of the 60 GHz millimeter-wave (mmWave) license-free ISM band, spanning from 57–71 GHz, is being considered as a potential solution for advancing next-generation industrial wireless communication and sensing applications, as well as for future technologies of beyond fifth-generation (5G) and sixth-generation (6G). This spectrum offers a large bandwidth of 14 GHz and experiences low spectral congestion. However, its effectiveness is hindered by significant path loss and high signal attenuation caused by oxygen absorption, posing additional challenges to design wideband, high-gain, compact, and cost-effective antenna solutions. This thesis encompasses three antenna design solutions offering high-performance metrics, aimed at next-generation mmWave industrial wireless applications and 6G technologies. The first antenna design is a compact and wideband 64-element planar microstrip array based on a hybrid corporate-series network. The array has the size of 2 cm × 3.5 cm × 0.025 cm and offers -10 dB impedance bandwidth over the entire 57–71 GHz, 1 dB gain bandwidth of 13 GHz from 57–70 GHz, low side lobe levels, and above 70% radiation efficiency in the whole band of interest. The inherent phase shift across the operating frequency in the series-fed antenna elements is leveraged to achieve frequency beamscanning over a scan range of 40° with less than 1 dB scan loss. The second antenna design is a compact, low-cost, high-gain, and planar 16-element linear array using the corporate feed technique. This design provides squintless high directional beamstowards the broadside over 7 GHz of bandwidth (57–64 GHz), and 1 dB gain -bandwidth of more than 3 GHz. This makes it a suitable candidate for industrial fixed wireless access communication scenarios that require large bandwidth and multi-gigabit data rate, such as highdefinition video signal transfer. An antenna with a broad 1 dB gain bandwidth can find various applications across different sectors. Primarily, such an antenna could be utilized in wireless communication systems where reliable and high-speed data transmission is essential. spans across mobile communication networks, enhancing signal strength and coverage for improved data throughput, and seamless connectivity for IIoT applications, enabling efficient data exchange in various settings such as critical industrial automation scenarios. Additionally, in radar systems, a broad 1 dB gain bandwidth antenna could improve target detection and tracking accuracy, enhancing situational awareness in surveillance applications. Overall, the broad frequency coverage provided by the 1 dB gain bandwidth antenna makes it versatile for a wide range of applications requiring robust and reliable wireless communication capabilities. The third proposed antenna solution is the hallmark of this thesis. A fully programmable electronically beamsteerable dynamic metasurface antenna (DMA) is designed and tested for the first time at 60 GHz band, thereby marking a significant milestone in advanced mmWave beamforming metasurface antennas. The 16-element linear DMA is based on novel digital complementary electric inductive capacitive (CELC) metamaterial elements whose radiation states can be dynamically controlled through a high-speed field programmable gate array (FPGA). The smart DMA can synthesize narrow beams, wide beams as well as multiple beams from a single aperture by generating different digital coding combinations. The proposed DMA is a low-cost and low-power smart beamforming antenna applicable to a diverse range of mmWave communication, sensing, and imaging avenues for smart wireless industries and 6G networks with agile beam-switching having a delay of less than 5 ns. The proposed DMA boasts striking features, including compact size, meticulously designed PCB, and software control via binary coding from a high-speed FPGA. Operating within the high-frequency mmWave ISM band, it encompasses a diverse range of license-free mmWave applications. The designed DMA achieves key performance metrics, boasting a bandwidth exceeding 2.16 GHz around 60 GHz, a high gain of above 9 dBi for most beamforming codes, and a radiation efficiency surpassing 60%. Additionally, it offers a versatile beam synthesis capability, enabling the generation of narrow pencil beams, wide beams, and multiple beams from a single DMA aperture. The proposed antenna solutions were fabricated, and tested through an in-house designed measurement setup which is elucidated in this thesis. Eventually, the striking futuristic applications of mmWave antennas, and their associated open research challenges are highlighted