Co-packaging Integrated Electro-optic Frequency Combs with Microwave Amplifiers

Integrated electro-optic frequency combs have recently gained attention for their operational simplicity compared to microresonator-based Kerr combs. Thin-film lithium-niobate and lithium-tantalate platforms have enabled broad spans in compact footprints, yet require Watt-level microwave input powers, making co-packaging with monolithic microwave integrated circuit (MMIC) amplifiers challenging. We present the design and packaging of a lithium-niobate photonic integrated circuit (PIC) carrying a triply-resonant electro-optic dual-comb with repetition rates near 30 GHz, co-packaged with two Qorvo TGA4509 gallium arsenide (GaAs) power amplifiers. Thin-film microwave networks were developed to interconnect the photonic and electronic components, using broadband microstrip launchpads and microstrip-to-ungrounded coplanar waveguide (CPW) transitions. Wire-bond compensation networks minimized parasitic inductance and return losses. The integrated package comprises 2.92 mm coaxial connectors and a shared heatspreader and achieves return losses below -15dB, gain of 18dB, and up to 2 W of driving RF power. This approach reduces footprint, reflections, and enables hybrid integration of microwave-photonic systems.