Active Balun Design for Next-Generation Telecom Satellite Frequency Converters

In this work, we describe the complete design flow of a 1.3–3.3-GHz active balun, exploited to generate a high-voltage swing differential local oscillator (LO) signal driving a highly linear doubly balanced resistive ring mixer. Both the LO active balun and the mixer are integrated into a Ku-band single chip monolithic microwave integrated circuits (MMIC) downconverter for the state-of-the-art telecom satellites. System performance has been maximized designing the different circuits by a holistic approach, which considers a non 50-
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environment. The experimental validation is carried out by means of an ad hoc time-domain load–pull test bench and shows that the LO active balun provides two quasi-sinusoidal, 180° out-phased, signals with 2.4-V peak-to-peak voltage to the input ports of the mixer over a very high-impedance loading condition.