A 38 GHz integrated phased-array antennas for PCS

Plans for future broadband personal communication systems urge the development of alternatives types of antennas that are small, light and cheap enough to be affordable to millions people. Our paper presents therefore an effort in the development of novel printed phased array antenna fed by CPW configuration to generate a dual polarization with a CPW feed line on single layer for the EHF band around a center frequency of 38 GHz. The array struture conjugates the advantages of aperture-coupled microstrip antenna and the wide range of flexibility and scope for innovation that uniplanar technology offers. Thus simplifies the structure of the array antenna by reducing the number of metallization level, from 3 down to 2, thereby making easier the integration of the active devices. In addition, this type of coupling is advantageous when applied to millimeter wave monolithic phased arrays. A unique feed design eliminates the competition for surface space between the antenna elements and the feed network. In addition, the ground plane shields the antenna half-space from spurious radiation emitted by feed lines and active devices. The array antenna is designed on a high dielectric constant substrate (εr = 9.9), which is close to the dielectric constant of GaAs and demonstrates the feasibility of integration of such an antenna structure into monolithic circuits. Finally, the newly developed array antenna provide alternative yet compact structures and should be useful in multitude of applications such wide-band digital indoor communication systems using MMICs on the same substrate and a combination of optical and radio transmission.