This paper briefly introduces some novel antenna techniques applicable to existing and upcoming wireless communication systems. First, miniaturized antenna designs are studied for various demands, such as multiband and broadband operations, circular polarization reception, clearance region reduction, and self-oscillating active integrated front-ends. Then, by utilizing dual-mode synthesized transmission lines, two innovative phased arrays are developed. One is a reflection-type retro-directive array (RDA) and the other is a two-element closely spaced array for MIMO system applications. Also, for RFID near-field systems, both magnetic and electrical coupling antennas are studied. Some applications for the above antennas are discussed too.