When Qualcomm introduced the QTM052 millimeter-wave antenna module in 2018, it was a wake-up call for the defense industry and anyone following the development of 5G. The device combines 64 dual-polarization antenna elements, delivering a combined RF output power of 50 dBm, a 5G NR transceiver, a power management IC, and an RF front end. It offers 800 MHz of bandwidth at 24.25 to 27.5, 26.5 to 29.5 GHz, 27.5 to 28.35 GHz, and 37 to 40 MHz and 2×2 MIMO. Notably, all those antenna elements were supported by beamforming and beam steering, essential ingredients, all in a package less than the length of a finger (Figure 1). Since then, other companies have developed their own beamforming ICs that would have been unimaginable a decade ago.
Beamforming is not new and has been used for decades, evolving from analog techniques to digital methods, although analog beamformers are still widely used. It originated in the early 20th century with analog systems. These early analog beamformers relied on physical adjustments to antenna arrays, using phase shifters and attenuators to control the beam direction and shape. Beamformer technology has long been critical to military radar and electronic warfare systems. The latest advancements in beamformer ICs have significantly enhanced the capabilities of these systems, enabling more precise target detection, improved jamming resistance, and increased operational flexibility.
During World War II, beamforming saw significant advancements as radar technology became crucial for military operations. Engineers developed more sophisticated analog beamforming techniques to improve radar performance and directional capabilities. In the post-war period, analog beamforming continued to evolve, finding applications in various fields such as radio astronomy, sonar, and wireless communications.
The advent of phased array antennas in the 1950s and 1960s enhanced analog beamforming capabilities, allowing for faster and more precise beam steering. Researchers began exploring digital beamforming techniques as electronic components became smaller and more potent in the 1970s and 1980s. Early digital beamformers were limited by the processing power available at the time but offered new possibilities for signal processing and beam control.
The 1990s saw rapid digital signal processing (DSP) technology advancements, leading to more sophisticated digital beamforming algorithms. This period marked a significant shift from analog to digital methods, with digital beamforming offering greater flexibility, adaptability, and performance. In the early 2000s, the widespread adoption of multiple-input multiple-output (MIMO) systems in wireless communications further propelled digital beamforming technology. MIMO systems leveraged digital beamforming to enhance spectral efficiency and channel capacity.
The emergence of 5G placed digital beamforming at the forefront of wireless communications. Massive MIMO systems, employing hundreds of antenna elements, rely heavily on advanced digital beamforming techniques to achieve high data rates and efficient spectrum utilization. Today, digital beamforming continues to evolve, with ongoing research focusing on millimeter-wave communications, cognitive radio, and adaptive beamforming algorithms. Integrating machine learning and artificial intelligence opens new frontiers in beamforming technology, promising even more efficient and intelligent systems.
For example, one of the world’s most advanced defense systems is the Next Generation Jammer (Figure 2), developed by Raytheon (RTX). NGJ is an advanced electronic warfare system that will replace the legacy ALQ-99 tactical jamming system used on EA-18G Growler aircraft. Incorporating highly advanced beamforming allows the NGJ to generate multiple simultaneous beams to engage multiple targets and dynamically adjust its beam patterns to respond to changing threat environments.
How Beamforming Works
For those who need a refresher, beamforming is a technique used to direct and shape the transmission or reception of radio waves. It enhances the signal strength in desired directions and reduces interference from undesired directions by adjusting the phase and amplitude of the signals at each antenna element.
There are three types of beamforming: analog, digital, and hybrid. Analog beamforming uses analog circuits to adjust the phase and amplitude of the signals using phase shifters and variable gain amplifiers to create a directional beam.
Digital beamforming digitizes the signals from each antenna element and then processes them using digital signal processing techniques to form the desired beam. This allows for more flexible and precise control compared to analog methods. However, digital beamforming tends to be more complex and expensive due to the need for high-speed digital processing, whereas analog beamforming is simpler. Hybrid beamforming combines both analog and digital beamforming techniques. The analog part handles initial signal processing, while the digital part fine-tunes and adapts the beamforming process.
Digital beamforming allows for creating multiple independent beams from a single array, significantly increasing the multitasking capabilities of radar and communication systems. Advanced beamformer ICs now incorporate high-speed ADCs and digital signal processors, enabling much of the beamforming process to occur in the digital domain. This shift towards digital beamforming has improved system flexibility, reduced hardware complexity, and enabled more sophisticated signal processing algorithms.
Modern phased array radar systems for defense applications utilize highly integrated beamformer ICs that can operate at frequencies up to 100 GHz. These ICs often incorporate GaN technology for high power handling capabilities and improved efficiency. Advanced packaging techniques, such as heterogeneous integration and 2.5D/3D IC stacking, have created compact, multi-function radar modules combining beamforming and signal processing (Figures 3 and 4).
The automotive industry has also benefited from advancements in beamformer ICs, particularly in developing automotive radar systems for advanced driver assistance systems (ADAS). Modern automotive radar beamformer ICs operate at frequencies around 77 GHz and can support multiple transmit and receive channels. Recent developments in automotive radar beamformer ICs have focused on improving resolution and range while reducing power consumption and cost. Some of the latest chips can support up to 192 virtual channels, allowing for high-resolution 4D imaging radar systems that can accurately detect and classify objects in the vehicle’s environment.
In addition, software-defined radio (SDR) is being applied to beamforming systems, allowing a single hardware platform to support multiple waveforms and operating modes. This flexibility is crucial for adapting to rapidly evolving threats and mission requirements.
Modern EW beamformer ICs support broad bandwidths from DC to well into the millimeter-wave region. These ICs enable the rapid scanning and analysis of the electromagnetic spectrum, the generation of complex jamming waveforms, and the use of direct digital synthesis (DDS) within beamformer ICs to reduce the cost and bill of materials.
The miniaturization of beamformer ICs (Figure 5) has also enabled the development of new classes of defense systems, such as small form-factor phased array radars for 5G systems, unmanned aerial vehicles (UAVs), and portable electronic warfare devices. These compact systems offer capabilities previously only available in much more extensive, fixed installations, greatly enhancing mobile forces’ situational awareness and electronic attack capabilities. Beamformer ICs such as the device shown in Figure 6 are also essential components for satellite communications transmit applications.
Looking to the future, several emerging technologies promise to advance the field of beamformer ICs further. One such technology is the integration of photonic components with electronic beamforming circuits. Photonic beamforming offers the potential for ultra-wideband operation, low loss, and reduced size and weight compared to traditional electronic systems. While still in the early stages of development, photonic-electronic integrated beamformer ICs could revolutionize both commercial and defense applications, particularly in the millimeter-wave and terahertz frequency ranges.
Another promising area of research is the application of advanced materials and manufacturing techniques to beamformer IC production. For example, using III-V semiconductors such as indium phosphide (InP) enables the creation of beamformer ICs with higher power handling capabilities and improved efficiency. Additionally, additive manufacturing techniques are being explored to produce customized, application-specific beamforming antennas and packaging solutions.
Artificial intelligence and machine learning are also set to play an increasingly important role in beamformer technology. AI-enhanced beamformer ICs could enable more adaptive and intelligent systems capable of autonomously optimizing their performance based on environmental conditions and operational requirements. In defense applications, this could lead to cognitive radar and electronic warfare systems that can learn and adapt to new threats in real time.
In conclusion, beamformer technology, particularly beamformer ICs, has seen remarkable advancements in recent years, driven by the demands of both commercial and defense applications. These developments have enabled more compact, efficient, and capable systems across various industries, from 5G communications to automotive radar and electronic warfare.
As research continues in areas such as photonic integration, advanced materials, and artificial intelligence, we can expect to see even more transformative innovations in beamformer technology in the years to come. These advancements will undoubtedly continue to shape the future of wireless communications, sensing, and electronic warfare, pushing the boundaries of what is possible in civilian and military domains.
