Prototype Reflectarray Antenna Demonstrates Low‑SWaP Anti‑Jam Tactical SATCOM

This prototype scanning reflectarray antenna, whose surface is made up of individual reflective elements, is designed to prevent satellite communications interference in low-power environments. (Image: Glen Cooper/Lincoln Laboratory)

June 10, 2026

Preventing adversaries from interfering with communications is crucial to national security. Tactical satellite communications (SATCOM) focus on securing reliable communications channels against adversaries in contested environments. In support of this mission, a team from MIT Lincoln Laboratory is building a prototype antenna characterized by low size, weight, power, and cost (SWaP-C).

Threats in contested environments — specifically proliferated low-Earth orbit (pLEO), where satellites must be as low-SWaP as possible because of the high volume of satellites present — are signal jamming and signals intelligence. Mitigating these threats through methods such as changing the shape of antenna beams in real time so that the ground user's signals can't be interfered with and preparing for future advanced capabilities are key to ensuring that satellites stay in communication with users on the ground.

"Looking toward the future challenges of tactical SATCOM, there is a clear need for novel approaches to radio-frequency (RF) aperture designs that are scalable and low SWaP-C without sacrificing functionality," said Michael Craton, a technical staff member in Lincoln Laboratory's Tactical Satellite Communications Group. "That is, we want to think about ways we can achieve exquisite performance using less expensive hardware. We want to anticipate future threats and have an idea about how to deal with them before they become a problem."

In the Laboratory's RF Systems Testing Facility, a team measures antenna patterns. The reflector (white) makes the measurement equipment (floor) appear much further away, simulating far-field outdoor conditions. (Image: Glen Cooper/Lincoln Laboratory)

One way to tackle the challenge of proliferated interference and jamming is through adaptive antenna arrays. Unlike single-element antennas, arrays are made up of multiple antennas that work together to guide and shape energy to and from the array. Adaptive arrays can change beam states quickly (a technique called adaptive beamforming) and change them in real time, depending on conditions, to prevent interference in certain directions by placing nulls, or signals that interfere with others. However, adaptive arrays have high SWaP, making them difficult to operate in SWaP-constrained environments like pLEO.

To address this problem, the team developed the Hosted Nimble Beamforming Anti-Jam Reflectarray (HoNi BAJR), a scanning reflectarray antenna prototype with a surface made up of reflective elements that can be individually controlled. When a signal hits the surface of the reflectarray, individual elements reflect energy with some phase shift to control the beam that is formed so that it blocks interference. Because the elements are very simple, the array can be scaled and controlled easily. Reflectarrays are similar to phased arrays, which consist of multiple elements that can be electronically controlled for quick beam changes, but scanning reflectarrays reflect signals toward a separate feed antenna, which eliminates much of the design complexity in conventional antenna arrays.

In addition to the reflective surface, reflectarrays feature a feed antenna. Unlike phased arrays that require amplifiers for each antenna element, they do not require amplifiers because signals are collected by the feed antenna and combined in free space; this lack of amplifiers for each element in the reflectarray lowers the SWaP required and helps with scalability, as the beamforming network does not have to be redesigned each time the size of the array is changed. A reflectarray uses much less power than a typical array, dropping the power consumption by about 95 percent.

The prototype HoNi BAJR reflectarray was designed for communications in a pLEO constellation with wide coverage across the horizon and can cater to low-power users in the presence of proliferated jamming. The array is sized to fit on a typical small satellite platform.

The HoNi BAJR prototype contains 256 small elements. (Image: Glen Cooper/Lincoln Laboratory)

The HoNi BAJR team tested the array's beamforming capabilities at the Laboratory's RF Systems Testing Facility , successfully demonstrating a high scan angle, which means the array can receive signals from a wide area. Their testing also showed that there is little loss in signal when synthesizing multipeak beams, or splitting the beam, indicating that reflectarrays can get signals to multiple users without information loss.

Suppressing interference (unwanted signals from equipment like cell phone towers or electrical devices) is also very important to ensuring the antenna works correctly. The HoNi BAJR team's work in this area is based on two programs funded through an internally administered R&D portfolio: Deployable Electronically Scanning Reflectarray (DESRa) and Phase Analog Beamforming (PhAB, which uses DESRa hardware). PhAB demonstrated that it was possible to adapt to nulls and mitigate signal jamming in real time.

However, in the dynamic signal environment of HoNi BAJR, there may not be time to adapt these beams fast enough for the signal environment. The team innovated a solution: creating regions of interference suppression instead of targeting individual points of interferences by shaping the side lobes of the beam. The technique faltered slightly in testing because of difficulty in controlling the side lobes, as they're sensitive to small signal changes. However, proper calibration (measuring effects from the instruments and the system to ensure the full signal received and transmitted by the antenna is accounted for) may help.

While key to ensuring a system works correctly, calibration is one of the biggest challenges of operating reflectarrays. Not much precedence exists for calibrating a scanning reflectarray, so the team is researching approaches. All aspects of the reflectarray (e.g., forming and shaping beams) will be improved by calibration, and full usage of the array will require a comprehensive understanding of calibration. Another major area the team is exploring is where reflectarrays can best be used.

This article was written by Ariana Gaines and Hailey Wahl for MIT Lincoln Laboratory (Lexington, MA). For more information, contact Ariana, This email address is being protected from spambots. You need JavaScript enabled to view it. .

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