Title :
A new linear amplifier using low-frequency second-order intermodulation component feedforwarding
Author :
Yang, Youngoo ; Kim, Bumman
Author_Institution :
Dept. of Electron. & Electr. Eng., Pohang Univ. of Sci. & Technol., South Korea
fDate :
10/1/1999 12:00:00 AM
Abstract :
A new linearization method by feedforwarding low-frequency second intermodulation component (f2-f1) is proposed. Drain voltage modulation by forwarding second intermodulation voltage improves linearity significantly. This new technique, which adopts a simple circuit configuration, has advantages in the stability and bandwidth due to the feedforwarding nature and shows a very good performance in comparison with other harmonic tuning circuits. Analytical derivation of low-frequency feeding voltage gain (β) to obtain perfect cancellation of IMD3 is presented. For verification of the proposed circuit topology, a two-tone test and a CDMA signal test at carrier frequency 2.15 GHz are performed and show about 18- and 10-dB improvement of IMD3 and adjacent channel power ratio (ACPR), respectively
Keywords :
circuit stability; circuit tuning; feedforward; intermodulation; microwave amplifiers; microwave circuits; 2.15 GHz; CDMA signal test; IMD3; adjacent channel power ratio; bandwidth; carrier frequency; circuit topology; drain voltage modulation; harmonic tuning circuits; intermodulation component feedforwarding; linear amplifier; linearization method; low-frequency second-order intermodulation; perfect cancellation; stability; two-tone test; Bandwidth; Circuit analysis; Circuit optimization; Circuit stability; Circuit testing; Circuit topology; Frequency; Linearity; Multiaccess communication; Voltage;
Journal_Title :
Microwave and Guided Wave Letters, IEEE
