Electrically Small Antennas with Miniaturized Impedance Matching Circuits for Semiconductor Amplifiers

Keiji YOSHIDA  Yukako TSUTSUMI  Haruichi KANAYA  

IEICE TRANSACTIONS on Electronics   Vol.E88-C    No.7    pp.1368-1374
Publication Date: 2005/07/01
Online ISSN: 
DOI: 10.1093/ietele/e88-c.7.1368
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Section on Recent Technologies of Microwave and Millimeter-Wave Devices Focusing on Miniaturization and Advancement in Performance with Their Applications)
Category: Active Circuits & Antenna
RF front-end,  miniaturized matching circuit,  electrically small antenna,  semiconductor amplifier,  coplanar waveguide,  

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In order to reduce the size of a wireless system, we propose a design theory for the broadband impedance matching circuit which connects an electrically small antenna (ESA) to a semiconductor amplifier. We confirmed its validity for the case of connection between a small slot loop antenna with a small radiation resistance of Ra =0.776 Ω and a semiconductor amplifier with high input impedance of ZL =321-j871 Ω with the aid of the simulations by the electrical circuits using transmission lines as well as the electromagnetic field (EM field) simulator. We also made experiments on this antenna with matching circuits using high temperature superconductor YBCO thin films on MgO substrates.