Why high-performance ADC & DAC systems are critical for radar, EW, and secure communications

In aerospace and defense electronics, analog-to-digital converters (ADCs) and digital-to-analog converters (DACs) are unsung heroes that bridge the analog physical world with digital processing. These components sit at the heart of radar receivers, electronic warfare sensors, software-defined radios, and many other high-frequency systems. As these applications demand ever higher performance – wider bandwidths, higher frequencies, greater dynamic range – advances in ADC and DAC technology have become pivotal for next-generation capabilities. In fact, as one industry observer noted, as data converters gain speed and bandwidth, designers can “take fresh looks at applications like radar and communications” and implement new ideas previously not feasible

Pushing the Envelope of Speed and Bandwidth

Modern defense systems operate in the GHz range and beyond, from S-band radars to millimeter-wave 5G communications and satellite links. Traditional converters often required intermediate frequency downconversion (mixing to a lower frequency) before digitisation, adding complexity and latency. Today, however, high-speed ADCs and DACs can directly sample RF signals at astonishing rates. For example, state-of-the-art converters reach sampling rates of 3–10 Giga-samples per second (GSps) or more, enabling direct RF sampling of broadband signals. A few years ago, engineers at Curtiss-Wright highlighted that emerging 12 GSps ADCs and 25GSps DACs could directly capture C-band satellite signals, eliminating the need for analog downconversion stages​This leap means simpler receiver architectures and the ability to digitise everything in-band for purely digital processing – a huge advantage in reliability and flexibility.

Rams Such high-frequency performance is crucial for advanced radar systems. Low Probability of Intercept (LPI) waveforms, for instance, spread radar energy over wide bandwidth to avoid detection. To intercept these stealthy signals, a receiver needs very wide bandwidth and high dynamic range. As Analog Devices engineers explain, an LPI radar might require an ADC that can simultaneously digitise hundreds of MHz (or even >1 GHz) of spectrum with excellent fidelity​ In other words, detecting a modern spread-spectrum radar or communication signal pushes converters to extremes. Underscoring this point, one technical article notes that to capture complex wideband waveforms disguised as noise, “a wider receiver bandwidth and higher dynamic range are needed… The ability of an ADC to simultaneously digitie 500 MHz and 1000 MHz… in a single band with high dynamic range helps tackle this challenge”​. Thanks to cutting-edge ADC technology, today’s military receivers can meet these demands, empowering missions like signals intelligence and electronic warfare where picking up an elusive signal can be a matter of life and death.

On the transmit side, high-speed DACs are enabling more agile and complex signal generation. Modern electronic attack systems and secure communications use fast-hopping frequencies and sophisticated modulation. A high-speed DAC, combined with direct digital synthesis techniques, can generate these waveforms on the fly across broad swaths of spectrum. For example, in next-gen satellite communications (SATCOM), fast DACs allow direct synthesis of Ka-band uplink signals without multiple frequency conversion stages, thus reducing hardware complexity while increasing signal agility.

Enabling New Architectures in Radar and Communications

The synergy of advanced converters with high-performance FPGAs is opening doors to architectures that were previously impractical. One concrete example is the rise of fully digital phased-array radars. In legacy systems, each antenna element might have an analog receiver path with mixers and filters. Now, designers are moving toward digitising at the element or sub-array level – sometimes called “digital beamforming” – where a fast ADC sits right behind each antenna element. This approach, though data-intensive, offers unrivaled flexibility (multiple beams, adaptive nulling, etc.). It’s made possible only by the latest generation of ADCs and the parallel processing power of FPGAs to handle the torrent of data. As Pentek and others describe, combining multi-gigabit ADC/DAC technology with powerful FPGAs enables new classes of embedded systems that can handle wideband signals in real-time and perform tasks like beamforming or channelisation digitally​ Essentially, the converters and FPGAs together form the backbone of the digital RF revolution.

The trend is evident in military SATCOM as well. Traditionally, a SATCOM terminal operating at, say, 5 GHz would downconvert to a lower IF before digital processing. That analog step added noise and complexity. Now, high-speed 12–25 GSps converters allow direct RF sampling, meaning the radio can convert the entire S-band or C-band signal to bits in one step​. This not only improves fidelity but also enables processing the full bandwidth in software (DSP algorithms can extract multiple channels, apply encryption, error correction, etc., all in the digital domain). Curtiss-Wright experts noted that this direct-sampling approach “eliminates the need for a front-end mixer” and allows the full communications bandwidth to be handled digitally​.​ The benefit is twofold: higher performance and easier upgrades (since changing a waveform is as simple as a firmware update rather than a hardware change).

Mission-Critical Reliability and Precision

In aerospace and defense, it’s not just about raw speed – reliability and precision of ADCs/DACs under harsh conditions are equally important. Converters in a fighter jet or a spacecraft must operate across extreme temperatures, vibration, and radiation (for space). They also must maintain calibration and low error rates over time. Vendors have responded with radiation-hardened or radiation-tolerant versions of high-speed converters for space applications, for example offering multi-gigasample ADCs that can survive orbital radiation levels​. On the precision front, parameters like effective number of bits (ENOB), signal-to-noise ratio (SNR), and spurious-free dynamic range (SFDR) are critical benchmarks. High-resolution (12- and 14-bit) ADCs ensure that even small signal nuances can be discerned amidst strong jamming or interference signals.

Modern ADC/DAC modules often integrate calibration and correction features to maintain performance. The clock stability feeding an ADC, for instance, directly affects its sampling accuracy; thus low-jitter clock circuitry and techniques like built-in self-calibration are employed. As a Microwaves & RF overview notes, maintaining accuracy and integrity of signals through the conversion process is paramount – any jitter or nonlinearity can degrade the whole system​. In mission-critical scenarios (say a radar tracking a fast missile), the timing precision of each ADC sample can affect target localisation. Therefore, advanced clock distribution and synchronisation (sometimes using GPS-disciplined oscillators or atomic clocks in high-end systems) are part of the overall high-frequency conversion solution.

In summary, advanced ADC and DAC systems serve as the linchpins of next-gen aerospace and defense electronics. They are powering breakthroughs by capturing and generating wider bandwidth signals than ever before, thus enabling technologies like digital beamforming radar, electronic warfare receivers for ultra-wide spectrum surveillance, high-speed secure communications, and more. As one industry article succinctly put it: defense systems from secure comms to surveillance all “rely on... highly integrated converters” at their core​ and finding the best ones – with sufficient speed, resolution, and reliability – is now a key design challenge. Going forward, as threats push to higher frequencies and more agile tactics, we can expect ADC/DAC technology (often paired with FPGAs) to continue advancing, effectively becoming the “eyes and ears” that empower digital brains to perceive and act in the analog world of missions.