Radar is increasingly associated with software-defined capabilities, adaptive sensing and digital control. Yet its evolution is also being driven by how electronic architectures manage control, timing and signal integrity as systems become more complex. As channel counts and performance demands increase, semiconductor integration is becoming increasingly important. Here, Ross Turnbull, Director of Business Development at Swindon Silicon Systems, explains how application-specific integrated circuit (ASIC) architectures are shaping next-generation radar systems.
Radar systems are becoming increasingly complex. Higher-resolution sensing, greater bandwidth and multi-function operation are driving up channel counts, while platforms impose tighter constraints on size, weight and power. As active electronically scanned array (AESA) architectures scale, maintaining reliable timing, signal integrity and control across thousands of channels becomes a significant design challenge.
In an AESA radar, beam steering depends on controlling relative phase, and often amplitude, across antenna elements. Each element or sub-array has a transmit/receive (T/R) module containing dedicated RF circuitry. The transmit path includes phase and amplitude control, a driver stage and FET-based power amplifier, while the receive path incorporates limiting and low-noise amplification.
Maintaining coherence at scale
Characterising a channel is no longer simply a matter of amplitude and frequency response. Timing alignment, phase stability, channel-to-channel skew, temperature sensitivity, supply variation and electromagnetic interference (EMI) all need to be considered.
Even small mismatches can affect beamforming. Phase or gain errors can produce beam-pointing errors and elevated sidelobes, reducing detection and tracking margins. Timing errors that vary with temperature or duty cycle can be particularly difficult to address through calibration alone.
Highly integrated architectures can help manage these effects by incorporating functions such as loopback, background phase and gain trimming, and digital compensation for analogue drift over temperature and lifetime.
FPGAs remain valuable where flexibility is important, particularly at moderate channel counts or where requirements are still evolving. However, scaling FPGA-centric architectures can introduce additional challenges. Signal chains may depend on separate converters, memory and driver stages, while interfaces and clock domains add propagation delay, skew and jitter.
As channel density and bandwidth increase, the limiting factor is therefore not necessarily processing capability. It can instead become the complexity of distributing signals reliably and maintaining coherence between devices.
The gate driver as a critical boundary
The gate-driver stage illustrates this challenge particularly well. Positioned between digital control and the transmit FET, it translates a digital command into repeatable electrical behaviour before RF power is generated. Small variations here can propagate directly into transmit performance.
In a conventional multi-device implementation, control signals may originate in an FPGA before passing through I/O routing, isolation and other interfaces to reach the driver and FET gate. Each boundary introduces opportunities for differences in timing and electrical behaviour.
An ASIC can consolidate more of this functionality. This lets one device carry the digital interface, control logic and multiple output drivers needed to match the FET characteristics, rather than spreading these functions across separate components. Channel-to-channel timing, drive strength and switching behaviour can consequently be managed within a common architecture.
Gate drivers sit close to large switching currents and steep dV/dt transitions, an environment where even small inconsistencies between channels are hard to avoid. Maintaining consistent behaviour across many discrete channels becomes increasingly difficult, so reducing device boundaries can make timing-critical functions easier to engineer and verify.
Managing system-level constraints
Integration can also address wider consequences of increasing radar complexity. High-power RF and dense digital processing create an electrically noisy environment, with every high-speed interface representing another potential emission or coupling path.
Consolidating functions within an ASIC can reduce interface count and simplify clock-domain management. Isolation requirements can be met within the silicon itself, while built-in self-test, loopback and digital observability can assist production testing and long-term diagnostics.
Distributed architectures consume power not only through processing but also through moving data between devices. Multiple components can create localised hotspots, while interconnects add losses. Greater integration can reduce these inefficiencies and provide a more predictable thermal profile.
Reliability is also critical for defence radar. Each additional component contributes to overall failure probability and each interface adds a further point where reliability can be compromised. An ASIC allows silicon, packaging, thermal behaviour and protection structures to be considered together.
Supporting long-lived radar platforms
Integration is not limited to new radar programmes. Many defence systems are being upgraded or sustained rather than replaced, and component obsolescence can become a significant issue for platforms that remain operational for decades.
ASICs can provide a route to recreating established functionality while retaining existing interfaces. Several discrete functions can be consolidated at a defined architectural boundary, such as the gate-driver stage, without necessarily requiring a wider redesign.
This allows legacy systems to benefit from modern semiconductor integration while limiting disruption to the surrounding architecture. Delivering these devices requires RF, analogue and digital design, verification, packaging and production test expertise, alongside long-term supply considerations.
Integration as radar architectures evolve
As radar systems continue to scale, performance comes down to how well signals can be generated, controlled and held stable from one end of the chain to the other. Algorithms and digital processing remain fundamental, but they cannot compensate indefinitely for timing errors, phase mismatches, thermal drift or unwanted coupling introduced by the underlying electronics.
ASIC integration provides one way of bringing these issues under tighter architectural control. By reducing device boundaries and consolidating timing-critical functions, it can help manage coherence, EMI, power, thermal behaviour, testability and reliability as channel counts increase.
The move towards integrated radar electronics is therefore about more than reducing component count: it is about making complex systems predictable and repeatable at scale.
