As satellite internet becomes an essential part of the new digital infrastructure, the demand for high-performance, miniaturized, and low-power RF chips is rapidly increasing. RF chips are the core components of satellite communication terminals, directly determining the efficiency of signal transmission and the overall system performance.

This article, based on the research findings of “Ka-Band Power Switching Chips for Satellite Internet,” presents the design and implementation of a highly integrated, high-efficiency Ka-band RF chip, providing key technical support for building compact and reliable satellite internet terminals.

1. Technical Requirements of RF Chips for Satellite Internet

Satellite internet systems are typically deployed in Low Earth Orbit (LEO), featuring wide coverage, high transmission rates, and low latency. Ground terminals and spaceborne equipment must operate within the Ka-band frequency range (27–40 GHz) to achieve stable signal transmission and reception.

This places strict requirements on RF chips:

High Integration: Reduce external circuits and discrete components to minimize system complexity.

High Efficiency: Improve Power Added Efficiency (PAE) and reduce total power consumption.

Miniaturization: Enable lighter, more compact terminal designs.

High Consistency: Ensure amplitude and phase uniformity across multiple channels for reliable system performance.

2. RF Chip Architecture and Process Selection

The Ka-band RF chip in this study adopts a 90 nm GaAs PHEMT (Pseudomorphic High Electron Mobility Transistor) process, known for high electron mobility, power density, and excellent high-frequency characteristics — making it ideal for Ka-band power amplification and switching circuits.

The chip integrates a Power Amplifier (PA) and a Single-Pole Double-Throw (SPDT) switch on one die, achieving monolithic signal amplification and channel switching.

Key design highlights include:

• Three-Stage Power Amplifier

The final stage employs a minimum-loss matching network, while the input and inter-stage matching use low-pass reactive circuits, significantly boosting efficiency while maintaining gain stability.

• Parallel SPDT Switch

A ¼-wavelength line parallel configuration combined with a positive-voltage control system limits insertion loss to below 1 dB, with a switching time ≤ 500 ns.

• Collaborative Cascaded Design

By embedding matching and filtering networks between amplifier and switch modules, impedance consistency is optimized, cascade loss is minimized, and overall chip performance is improved.

3. Key Performance Metrics and Test Results

The RF chip measures only 2.25 mm × 1.40 mm, demonstrating outstanding performance in the 27–31 GHz frequency band:

Small-signal gain > 22 dB, gain flatness ±1 dB

Output power at 1 dB compression > 21.5 dBm

Power Added Efficiency (PAE) > 32%, outperforming most similar Ka-band RF chips

Channel amplitude consistency < 0.5 dB, phase consistency < 4°

Total power consumption < 0.5 W, ideal for low-power satellite terminals

Tests confirm that the RF chip meets its design goals in terms of efficiency, integration, and channel uniformity, making it highly suitable for satellite internet front-end transmitters.

4. The Value of RF Chips in Satellite Communication Systems

Traditional satellite terminals rely on discrete power amplifiers and switches, which result in larger size, higher interface losses, and poorer channel consistency.

The proposed monolithic Ka-band RF chip solves these issues through process-level and circuit-level optimization:

System Miniaturization: A single chip replaces multiple modules, reducing front-end size.

Enhanced Performance: High-efficiency and low-loss design improves overall communication quality.

Mass Production Consistency: The GaAs PHEMT process ensures uniform and reliable chip performance.

These RF chips can be widely applied in ground terminals, vehicle-mounted stations, airborne communication systems, and more, forming a hardware foundation for efficient and reliable space–ground integrated networks.

5. Conclusion and Outlook

This paper introduces a high-performance Ka-band RF chip tailored for satellite internet. Based on GaAs PHEMT technology, the chip integrates a power amplifier and switch circuit using a cascaded design that achieves high gain, high efficiency, and compact size.

Experimental results validate its excellent performance in the 27–31 GHz band, showcasing strong potential for real-world engineering applications.

Looking forward, as satellite internet merges with 5G/6G networks, RF chips will continue evolving toward higher frequencies, broader bandwidths, multi-channel integration, and reconfigurable architectures. Future research will focus on RF chips with embedded security mechanisms and intelligent beamforming capabilities, driving the next generation of satellite communication systems.