2.4 GHz circular-polarization LNA receiving-type and PA transmitting-type active patch antennas for ISM band wireless communications

S. Y. Lin, H. R. Chuang

Research output: Contribution to journalArticle


This paper presents the design, implementation, and measurement of amplifier-type circular-polarization (CP) active patch antennas for 2.4 GHz ISM-band wireless communication applications. The RF amplifier can be a low-noise amplifier (LNA) (23-dB gain and 2.8-dB noise figure) for receiving or a power amplifier (PA) (about 20-dB gain and 20-dBm output power) for transmitting at 2.4 GHz ISM-band. Using a Lange-coupler for two orthogonal feeds creates a 2.4 GHz circular-polarized square patch antenna. The spectral-domain electric field integral equation (SD-EFIE) technique is employed to accurately determine the patch antenna dimension, the antenna input SWR, current distribution, and radiation patterns. Finally, the semi-balanced amplifiers (by using PAs or LNAs) are designed and integrated with the patch antenna to form a transmitting or receiving type circularly-polarized active microstrip antenna. The patch-antenna/amplifier modules are fabricated on two FR-4 substrates with the ground planes soldered together. Compared with the stand-alone patch antenna, the combined patch-antenna/amplifier module has a much wider bandwidth. Potential applications of CP active patch antennas include base station antennas of ISM-band cordless telephones or wireless local area networks (WLAN).

Original languageEnglish
Pages (from-to)167-173
Number of pages7
JournalJournal of the Chinese Institute of Electrical Engineering, Transactions of the Chinese Institute of Engineers, Series E/Chung KuoTien Chi Kung Chieng Hsueh K'an
Issue number2
Publication statusPublished - 1998 May 1


All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering

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