Effects of Output Low Impedance Termination to Linearity of GaAs HBT Power Amplifier

• Main Authors: Koh, Minghao, Ellis, Grant, Teoh, Chin Soon
• Format: Conference or Workshop Item
• Published: 2010
• Subjects: TK Electrical engineering. Electronics Nuclear engineering
• Online Access: http://eprints.utp.edu.my/4754/1/ICIAS_KMH_28-4-10.pdf; http://eprints.utp.edu.my/4754/

Improving linearity over a broad band is a major goal in RF design. This paper demonstrates that adding a low impedance termination at the envelope frequency (2 – 1) to the output of a gallium Arsenide (GaAs) Heterojunction Bipolar Transistor (HBT) distributed amplifier (DA) improves the third order output intercept point (OIP3) over a bandwidth of 2.5 GHz to 3 GHz by 1.6 to 3.4 dB. The low impedance termination is easily implemented using an external series inductor-capacitor network (LC trap) to the Monolithic Microwave Integrated Circuit (MMIC) DA. The addition of the trap causes no reduction to the in-band gain, return loss, and P1dB.