Broadband and Multi-Band Planar Antenna Array Technology for Frequency-Agile, Low Side Lobe Wireless Communication

Background

The field of phased array antennas is central to modern wireless communication systems, including 5G/6G networks, radar, and satellite communications. As demand for higher data rates and more reliable connections grows, there is an increasing need for antennas that can operate efficiently over wide frequency ranges—so-called broadband or multi-band operation. This is especially critical in millimeter-wave (mmWave) bands (30–100 GHz), where spectrum is plentiful but propagation losses are high, requiring advanced beamforming to focus energy and maintain link quality. Planar antenna arrays, which can be integrated with electronics on a single substrate, are particularly attractive for compact, high-performance systems. However, achieving wideband operation with stable beam patterns and low interference remains a significant challenge, driving ongoing research into new array architectures and design methodologies.

Current approaches predominantly use uniform linear arrays (ULAs) with elements spaced at half the wavelength of the lowest operating frequency. While this configuration is optimal for narrowband operation, it becomes problematic at higher frequencies within the array’s operating range. As frequency increases, the fixed physical spacing between elements translates to larger electrical spacing, violating the spatial sampling criterion and resulting in spatial aliasing and grating lobes—undesirable beams that can be as strong as the main lobe. These artifacts degrade beam steering accuracy and spectral efficiency, undermining the benefits of phased arrays in broadband applications. Attempts to reduce element spacing to avoid these issues introduce severe electromagnetic coupling between elements, which impairs impedance matching and radiation efficiency. Furthermore, conventional array synthesis and optimization techniques struggle to maintain low side lobe levels and stable performance across wide bandwidths, limiting the effectiveness of current phased array solutions for next-generation wireless systems.

Technology

This technology is an advanced broadband and multi-band planar antenna array system designed to overcome the spatial aliasing and grating lobe limitations of conventional uniform linear arrays, especially for frequency-agile wireless communications in the 30–100 GHz range. It employs non-uniform sparse array architectures—such as Raised Power Series, aperiodic tiling, multi-turn circular, and rotationally symmetrical “pizza” arrays—where element positions are optimized using iterative convex optimization or constraint genetic algorithms to minimize broadband side lobe levels. Each array element is a broadband dual-port antenna with a 1-bit switching aperture, allowing seamless selection between low and high frequency bands while maintaining stable radiation patterns. These elements are integrated with ultra-wideband beamformer RFICs on a planar, multi-layer HDI PCB, with each RFIC offering independent amplitude and phase control through co-designed power amplifiers, SPDT switches, 5-bit phase shifters, variable gain amplifiers, and IQ direct up-converters, all optimized for wideband performance and efficient thermal management.

What differentiates this solution is its holistic approach to broadband phased array design, combining innovative non-uniform sparse array topologies with algorithmic optimization and tightly integrated RF front-end circuitry. Unlike traditional arrays that suffer from grating lobes and coupling issues at wide bandwidths, this system’s optimized element placement ensures low side lobe levels and robust beam steering across a 3:1 frequency range. The modular “pizza” array design enables scalable manufacturing and repeatable feeding networks, while the co-designed RFICs achieve industry-leading bandwidth, phase accuracy, and gain control. The dual-port antenna elements with band-select switching provide stable performance across multiple mmWave bands, making the system uniquely suited for next-generation 5G/6G networks and multi-band sensing applications. This integration of advanced array synthesis, broadband antenna engineering, and high-performance RFICs delivers a compact, frequency-agile phased array platform that outperforms state-of-the-art solutions in both spectral efficiency and practical deployability.

Benefits

• Enables broadband and multi-band operation across wide frequency ranges (30–100 GHz) with stable radiation patterns and low side lobe levels.
• Overcomes spatial aliasing and grating lobe issues inherent in conventional uniform linear arrays through optimized non-uniform sparse antenna array topologies.
• Reduces inter-element coupling by maintaining minimum element spacing, improving impedance matching and radiation efficiency.
• Employs advanced optimization algorithms (2D convex optimization and constraint genetic algorithms) for precise antenna element placement, minimizing broadband side lobes.
• Integrates broadband dual-port antenna elements with 1-bit band-select switching for seamless low and high band operation.
• Incorporates ultra-wideband beamformer RFICs with independent amplitude and phase control, enabling agile beam steering and frequency agility.
• Utilizes co-designed RF front-end components (power amplifiers, switches, phase shifters, VGAs, mixers) optimized for wideband performance and low power consumption.
• Supports scalable, modular array architectures (e.g., rotationally symmetrical “pizza” arrays) facilitating practical manufacturing and deployment for next-generation wireless systems.

Applications

• 5G/6G mmWave base stations
• Automotive radar and sensing
• Satellite communications terminals
• High-speed wireless backhaul
• Advanced wireless imaging systems

Additional info

These systems and methods detail broadband and multi-band planar antenna arrays. They utilize non-uniform sparse architectures, optimized via algorithms, to overcome spatial aliasing and grating lobes across 30-100 GHz. Each element is a dual-port antenna with band switching, integrated with ultra-wideband beamformer RFICs for independent amplitude and phase control.