Previously, higher wireless data transmission rates were achieved through increasingly complex modulation schemes, which encapsulated more bit data in the same spectrum slice. This solution has currently reached its practical application limit, so in the future, whether it is designed for commercial 5G throughput applications or high-capacity military links, it will rely on wider bandwidth rather than denser modulation. This technological transformation has forced designers to turn to millimeter wave (mmWave) spectrum, which can achieve various new functions through abundant spectrum resources, but also brings a series of completely different design challenges.
The 5G communication system is benefiting from years of research work initially conducted by defense enterprises. For example, phased array antenna technology originating from the national defense field can achieve beam scanning and multi-target synchronous tracking, and is now widely adopted in 5G applications for simultaneously transmitting multiple data streams to multiple users. Commercial systems are increasingly operating in frequency bands such as 28 GHz and 39 GHz to obtain the bandwidth required for multi gigabit links.
Analog Devices, Inc. and other companies utilize their accumulated millimeter wave expertise in defense industry applications to provide standard components that meet both defense performance requirements and commercial infrastructure manufacturing needs. Advanced high-frequency IC surface mount technology contributes to the large-scale deployment of 5G technology.
Both 5G and the defense industry rely on advanced high-frequency hardware. 5G networks are optimized for specific narrow spectrum slices to maximize throughput, while military applications such as electronic warfare (EW) require wider operating bandwidth to ensure spectrum sensing capabilities. Despite these differences, the development of wide modulation bandwidth in the 5G field has spurred a symbiotic benefit at the manufacturing level.
The integration of millimeter wave technology in these fields has achieved the manufacturing scale required for commercial deployment. In addition, this fusion greatly reduces the related costs of relying on expensive small batch "chip and wire" assembly processes to produce military application products.
This scale relies on highly integrated radio frequency ICs (RFID), phased array modules, and easy-to-use testing solutions. Nowadays, these solutions are increasingly offered to small design companies, which in the past lacked the budget or specialized capabilities of large defense contractors.
This mutual promotion also forms a shared testing infrastructure. In the past, testing phased array antennas at 28 GHz and 39 GHz required expensive large anechoic chambers. The widespread adoption of 5G has promoted the development of affordable ready-made OTA testing solutions, which defense companies can use to quickly solve product development challenges without requiring significant financial investment. The popularity of these validated and directly deployable building blocks allows design companies of all sizes to use millimeter wave as an easy to manage subsystem, making it easier to transform promising millimeter wave applications from schematic diagrams into deployable hardware.
Spectrum innovation
For decades, wireless technology innovation has employed two fundamentally different methods: encoding more information into each different signal state (symbol), or expanding the spectral space used for transmitting information.
Simpler modulation schemes prioritize robustness and signal integrity, while more complex schemes improve data throughput by transmitting more bits per symbol. The basic modulation method uses a small amount of information (such as a single bit) to represent each symbol. Designers can improve system performance by using more complex modulation schemes such as QAM to encode more information for each symbol, or by accessing wider spectrum channels in higher frequency millimeter wave bands.
Modulation determines how data is packaged onto a carrier, while power amplifiers (PAs) ensure that data bits reach their intended destination. In the commercial 5G field, power amplifiers prioritize efficiency and linearity within designated frequency bands to support high-throughput phased arrays. However, in military systems, a wider frequency range and higher power are usually pursued to improve radar clarity, satellite communication capabilities, and usability.
Even with the advancement of modulation technology, there is still a fundamental limit to the amount of data pushed through specific carrier frequency (FC) bands. One key principle is that data throughput is directly related to channel width, which is the bandwidth of the modulated signal (FBW). To achieve higher data transmission rates, a wider carrier frequency channel is required, just like switching from a crowded single lane highway to a ten lane highway (Figure 1).