New compact broadband phase shifters using coupled lines

This paper presents two types of phase shifters using parallel coupled lines as compact and broadband couplers. Phase shifts are enabled by varying the varactor capacitances or by switching the PIN diode ON/OFF. Both have shown about 40% bandwidth within ±3.5° phase error. While an adjustable phase control over 65° is obtained by the phase shifter with varactor diodes, 180° is yielded by that with PIN diodes. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 36: 399–400, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.10775