Reflectarray Antenna Design for Modern Space Missions

In recent years, there has been significant interest in reflectarray antennas and how they can be used to enable high-performance antenna design for the next generation of communication satellites.

Why Reflectarray Antenna Design Matters in Modern Missions

What is a reflectarray antenna?

A reflectarray is an alternative to a traditional reflector antenna and offers a low-cost, high-gain solution for a wide range of applications, including modern satellite and space missions. A reflectarray consists of a feed element and a typically planar surface with the unique ability to control the phase of the reflected field across the surface. This control enables precise reflectarray antenna design that produces a focused or shaped beam from a planar surface.

A planar pencil-beam reflectarray in an anechoic measurement chamber.

The history of reflectarrays dates back to the 1960s when they were constructed using an array of short-circuited rectangular waveguides. By varying the length of these waveguides, engineers could control the reflected phase and form a focused beam, even from an almost flat antenna structure. However, these early waveguide arrays were heavy and complex to manufacture.

A significant breakthrough in reflectarray antenna design came with the invention of the printed circuit reflectarray in the 1980s. Here, the waveguide array is replaced by a dielectric circuit board with a ground plane underneath and printed elements on top. The elements can be, for example, simple rectangular patches of conducting material. The incident field is diffracted at the edges of the patches and propagates further in the dielectric material beneath the patches, from which it is reflected back to free space. By adjusting the size of the patches, the phase of the reflected field can be controlled. This configuration is thinner, lighter, and less expensive than the previous waveguide arrays.

Since then, much effort has been devoted to improving the simple patch elements with respect to phase range, bandwidth, polarisation, and other performance parameters. A huge variety of array-element designs for many different purposes can now be found in the literature. These include contoured beams, LP (Linear Polarisation) to CP (Circular Polarisation) conversion, and also advanced designs for multibeam applications in which RHCP (Right Hand Circular Polarisation) and LHCP (Left Hand Circular Polarisation) are reflected in different directions..

A dual-band dual-polarised doubly curved reflectarray for multiple spot beam applications.

Research paper: Reflectarrays in future satellite antenna systems: Application and design

What is the benefit of reflectarray antennas?

The key benefit of reflectarray antennas is the ability to focus radiation using a passive, planar, and lightweight structure. Additionally, these antennas are generally easier and more affordable to produce than traditional curved reflectors, making them ideal for compact platforms such as CubeSats and nano-satellites.

Watch video: M-Argo: ESA’s asteroid-targeting CubeSat

A 8U CubeSat with a reflectarray antenna in an anechoic measurement chamber.

The design flexibility offered by patch geometries has led to many innovations in reflectarray antenna design. Engineers can now create reflectarrays tailored for specialised beam shaping, contoured coverage, or multi-spot beam performance.

Available tools for reflectarray antenna design

While traditional reflector antennas can be designed with relatively simple modelling tools, reflectarray antenna design requires more advanced methods. Any decent design must use a periodic solver to compute the electromagnetic response from the array elements, followed by an optimisation algorithm that tunes the geometry of thousands of elements to meet design goals.

Historically, this complexity limited the adoption of reflectarrays. However, dedicated commercial software like QUPES by TICRA has changed this. QUPES is built specifically to analyse and optimise quasi-periodic surfaces such as reflectarrays, frequency-selective surfaces, and transmitarrays. Its speed and efficiency make it possible to complete reflectarray antenna designs with performance comparable to that of conventional reflector antennas.

When used in combination with other products in TICRA Tools, QUPES allows the user to design advanced high-performance reflectarray systems optimised for mission performance.

Visit product page for QUPES.

Whether you’re designing a single reflectarray antenna or exploring complex reflectarray antenna configurations, TICRA’s software equips engineers with the precision and flexibility needed for today’s mission demands. Get in touch to learn how we can support your project.