A new wideband small size, multifrequency phased array antenna with beam scanning capability has been designed and developed at X-, K- and Ku-band frequency ranges. The phased array design utilizes multi-function wideband RF antenna (T/R modules) elements, which are realized by integrating a wideband transmitter source (RF amplifiers), low noise amplifier (LNA), a diplexer and a multi-octave band planar linear tapered slot line antenna (LTSA). The array uses a multi-line time delay phase shifter controlled by a piezoelectric transducer (PET) and has demonstrated beam scanning capability of +/-20 degrees at 20 GHz. The multi-line phase shifter controlled by the PET has insertion loss of less than 1 dB and phase shift of 0 to 360 degrees up to 20 GHz, thus providing a high efficiency and compact phased array antenna design. The new phased array technology will have a far-reaching impact on future satellite communications, cross-link communications between satellites, global communications, surveillance, planar active arrays, sensors.