Slotted Waveguide Array Antenna

The Anywaves Slotted Waveguide Array Antenna is designed for satellite payload applications that require high gain (above 20 dBi) with high power handling, low profile and structural robustness. Primary applications include synthetic aperture radar (SAR) payloads, where the antenna must transmit and receive high-power radar pulses with precise beam control; inter-satellite link (ISL) communications, where the narrow beam and gain maintain link budget across long distances; and high-data-rate downlinks in Ku or Ka band, where gain directly determines achievable throughput. It is a custom product: the exact frequency, gain, footprint and beam characteristics are defined jointly with the customer for each mission.

A full-metal antenna is one where the entire RF-carrying structure — the waveguides, the radiating slots, the feed network — is made exclusively from metal, without any dielectric substrate (PCB laminate, ceramic, or similar). This has three significant consequences for payload applications. First, it eliminates ESD: metal structures cannot accumulate electrostatic charge in the way that dielectric surfaces can, which is critical in the harsh plasma environments of LEO and GEO orbits. Second, it provides thermoelastic robustness: metal expands and contracts uniformly, so the antenna maintains its shape and RF performance across the extreme thermal cycles of space without differential expansion stresses. Third, it enables high power handling: the absence of dielectric material removes the primary failure mode for high-power antennas (multipaction and dielectric thermal degradation), allowing the antenna to handle the power levels required by SAR transmit functions without derating.

Fractional bandwidth is the ratio of the antenna’s usable bandwidth to its centre frequency, expressed as a percentage. A 5% fractional bandwidth at Ka band (approximately 30 GHz centre) corresponds to an absolute bandwidth of about 1.5 GHz. At Ku band (approximately 12 GHz), it corresponds to about 600 MHz. This bandwidth is sufficient for the majority of SAR and ISL applications, which typically require a few hundred MHz to a few GHz depending on the waveform and data rate. If a wider bandwidth is required for a specific mission, Anywaves engineers can discuss alternative design options.

Development timelines for custom payload antennas depend on the complexity of the requirements, the target TRL level, and the testing scope agreed with the customer. A typical development programme follows standard space hardware milestones: Preliminary Design Review (PDR), Critical Design Review (CDR), Test Readiness Review (TRR) and Test Review Board (TRB). Anywaves’ project managers and engineers work with the customer from the initial requirements definition through to delivery of the qualified flight hardware. Contact us with your programme timeline and requirements to discuss what is achievable.

Both products are custom-designed high-gain flat antenna solutions for Ku/Ka-band payload applications, but they differ in architecture and trade-offs. The Slotted Waveguide Array is a full-metal active aperture: it radiates directly from slots cut into the waveguide walls, with no separate reflector. This gives it high power handling, ESD immunity and a very low profile (below 10 mm). The Reflectarray uses a planar array of passive phase-shifting elements illuminated by a feed horn, which can achieve very high gain over a large aperture more easily but typically involves a larger overall volume and different thermal behaviour. The right choice depends on the mission’s gain requirement, power level, available volume and deployment scenario. Anywaves engineers can guide the trade-off based on your specific requirements.