Giving small satellites a bigger impact with an advanced wireless chip

The world is steadily moving toward seamless, global connectivity through satellite constellations. Small satellites—weighing up to 10 to 100 kgs—are further enhancing the connectivity with their flexibility and scalability. But the application of small satellites often faces a significant challenge in their ability to accept communication beams.

Satellites communicate using communication beams, which are electromagnetic waves. In some waves, the electric field rotates in a spiral, and these waves are called circularly polarized beams.

Based on the direction of the rotation, the beams can be either in right-hand circular polarization (RHCP) or in left-hand circular polarization (LHCP). Small satellites weighing in the 10s of kgs can only handle single polarization beams, whereas bulkier satellites often require higher power to handle both polarized beams.

Driven by this need, a team led by Associate Professor Atsushi Shirane at Tokyo Institute of Technology, which was integrated into the Institute of Science, in Tokyo, Japan, has successfully developed a novel Ka-band wireless chip for small satellite communication systems that can independently control the two circularly polarized beams—a property that was unachievable with conventional technologies.

The research was carried out in collaboration with Axelspace, Japan, and the findings were presented at the IEEE International Solid-State Circuits Conference (ISSCC 2025), held from February 16–20, 2025, at the San Francisco Marriott Marquis in California.

“Conventional satellite communication receivers often struggle to handle both RHCP and LHCP beams independently,” explains Dr. Shirane. “To overcome this, we designed a switch-type quadrature-hybrid within a wireless chip that can pick up both left-hand and right-hand circularly polarized signals.”

A quadrature-hybrid is a special circuit that splits a signal into two parts, with one part delayed slightly to create a 90-degree phase difference. It breaks a circularly polarized signal into two straight signals and allows the chip to compare them. This helps to determine whether the signal was spinning left or right and therefore enables it to recognize both types of polarization used in satellite communication.

The ability to independently steer both types of circularly polarized beams allows for greater communication flexibility, which is a critical requirement for satellite-based networks, especially as demand surges for broadband access in underserved and remote areas. Moreover, this innovation also doubled the number of controllable beams the satellite could handle, significantly improving the system’s capacity.

One notable benefit is that the chip has been fabricated using the widely adopted complementary metal-oxide-semiconductor (CMOS), which is a low-power, fast, and compact technology used to build integrated circuits. This adds to the cost-effectiveness and scalability of the receiver, which is crucial for real-world deployments.

“Our receiver chip works in Ka-band frequency, known for its high-speed data transfer,” emphasizes Dr. Shirane. “In fact, it’s the very same frequency band harnessed by cutting-edge satellite networks like SpaceX’s Starlink.”

To verify its performance, the receiver chip was tested within a prototype satellite-mounted communication device and was subjected to over-the-air measurements. This confirmed the chip’s performance in handling circular polarization beams while maintaining the fundamental requirements for satellite communication systems.

The technology is a fundamental leap forward for global connectivity and is expected to have a profound impact on satellite communication infrastructure. Further developments could enable broader high-speed connections, offering coverage across vast geographic areas that were previously unreachable.

In an increasingly connected world, this innovation marks a new chapter for satellite-based communication—one that promises to bridge digital divides and make global communication efficient, affordable, and accessible for all.