A microwave microstrip probe-fed antenna with an integrated voltage-control
led phase shifter is investigated The phase shifter used is a microstrip 90
degrees hybrid loaded by two varactor diodes, allowing a 40 degrees phase
shift. It is integrated on the antenna due to multilayer technology. Radiat
ion patterns in the E- and H-planes are similar to those obtained with a si
mple passive patch. (C) 1999 John Wiley & Sons, Inc.