MILLIBEAM introduces H4Q1H1 GaN RF power amplifier, a high-performance device from its Heaviside product line designed to address demanding defence and space applications across the X-band spectrum. Covering 8-12 GHz, the amplifier supports a wide range of use cases, including radar systems, ITU-allocated deep space communications, and electronic warfare operations such as jamming and signal detection.
The H4Q1H1 delivers 5W output power with a 37 dB small-signal gain and maintains a gain flatness of ±1 dB across its operating band. It achieves a peak power-added efficiency (PAE) of 39%, while offering unconditional stability from DC to 40 GHz. Engineered for simplified integration, the device minimizes RF and DC connectivity requirements, featuring single-pin interfaces for RF input, RF output, and biasing (VGG and VDD). Fully 50Ω matched at both input and output, it requires no external matching or biasing components and is available in a compact 4 mm × 5 mm QFN package or as a bare die.
MILLIBEAM highlights the amplifier’s suitability for phased-array architectures, where space and efficiency are critical. With a half-wavelength element spacing of approximately 15 mm at 10 GHz, the compact footprint enables dense lattice integration without compromising array performance. The high gain eliminates the need for additional driver stages, reducing system complexity and supporting size, weight, and power (SWaP) constraints typical in electronic warfare and jammer payloads.
A key differentiator of the H4Q1H1 is its wide 40% fractional bandwidth—significantly broader than the 10–15% typically seen in RF power amplifiers. Achieving this level of bandwidth requires careful management of gain flatness and efficiency, which MILLIBEAM addresses through internal harmonic control, broadband impedance transformation, and minimization of package-related parasitics. The design also reflects optimized transistor sizing and process selection to balance bandwidth, losses, and thermal performance.
The company also emphasizes the importance of unconditional stability in GaN devices. Due to inherently high gain at lower frequencies, poorly stabilized X-band amplifiers can oscillate outside their intended operating range, potentially causing device failure. This risk is particularly pronounced in phased-array systems, where element coupling creates unpredictable impedance environments. By ensuring stability from DC to 40 GHz, the H4Q1H1 mitigates these risks under any passive load condition.
For integration, the device operates with a 25V drain supply, with a gate bias of approximately −2.8V applied before the drain voltage. A target quiescent drain current (IDQ) of 360 mA is specified. PCB design requires standard 50 Ω transmission lines at RF ports, along with 4.7 µF decoupling capacitors on each bias rail placed close to the device pins. The amplifier has been characterized under pulsed continuous-wave (CW) conditions, and MILLIBEAM advises customers to consult directly for application-specific operating parameters.
The H4Q1H1 is part of MILLIBEAM’s broader Heaviside GaN power amplifier portfolio. The company is offering simulation models, evaluation units, and technical support, with datasheets and samples available upon request.
Click here to learn more about the H4Q1H1 from MILLIBEAM.
