Using baluns for highly integrated RF modules

Today, RF/MMIC engineers designing multichip modules require "circuit-level" EM simulation and modeling to meet the increased demands for higher levels of system integration. Modules providing full system-level functionality require passive support circuitry in addition to typical active components. These passive components typically include circuits such as 90-degree couplers, 180-degree couplers, in-phase couplers, filters, diplexers, and transmission line structures.

Baluns are important support circuitry used in high-frequency circuit design. The 180-degree balun is a major component in heterojunction bipolar transistor as well as pseudo high-electron mobility transistor push-pull amplifiers, balanced mixers, balanced frequency multipliers, phase shifters, balanced modulators, dipole feeds, unbalanced to differential converters for differential signaling, and numerous other applications. Additionally, analog circuits requiring balanced inputs and outputs to reduce noise and minimize high order harmonics, and improve the dynamic range of the circuits are also good candidates to benefit from this type of balun structure.

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