Transistor-Eingangsanpassung mit Transformator

Abstract

An RF power transistor package includes an input lead, an output lead, and an RF power transistor having a gate, a drain and a defined gain over an RF frequency range for which the RF power transistor is configured to operate. The RF power transistor package further includes a transformer electrically isolating and inductively coupling the gate of the RF power transistor to the input lead. The transformer is configured to block signals below the RF frequency range of the RF power transistor and pass signals within the RF frequency range of the RF power transistor. The RF power transistor package also includes a DC feed terminal for providing DC bias to the gate of the RF power transistor.

Description

technical field [0001] This application relates to RF power transistors, and more particularly to input matching for RF power transistors. Background technique [0002] High power RF transistors such as LDMOS (Laterally Diffused Metal Oxide Semiconductor) transistors have input and output impedances (high Q impedance) significantly below 50 ohms, whereas normal RF circuits must be matched to 50 ohms. In order to achieve impedance matching to 50 ohms, RF transistors are usually designed with matching circuits integrated in the packaged transistor at the input and output of the transistor. The matching network helps reduce the Q of the packaged transistor, making it easier to match to 50 ohms. Typically, impedance improvement can only be achieved within a narrow frequency range. In addition, matching networks help shape the frequency response of transistors and amplifiers so that there is high gain at the desired operating frequency while suppressing gain outside that freque...

AI Technical Summary

Problems solved by technology

However, this implementation does not inhibit the maximum available gain at low frequencies, so high gain at low frequencies causes stability, robustness, and linearity correction issues when the source and / or load are mismatched to 50 ohms

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