A new type of microstrip array fed by a purely TEM feed network

The presence of the dielectric in microstrip arrays presents a number of disadvantages (losses, dispersion limitations in the range of the design parameters and price). A microstrip array printed on a very thin film and separated from the ground-plane by a sheet of foam were successfully designed, however the fabrication difficulties associated with the use of foam make this type of antenna far from ideal for solving all the problems mentioned above. A new type of array is presented. Rather than using a superstrata geometry, the ´printed circuit´ is cut out of a sheet of metal and supported in ´strategic points´ by plastic standoffs. The main motivation of this work was to obtain large microstrip arrays which exhibit a higher efficiency than the conventional ones, and can be fabricated using large quantity production techniques. Microstrip arrays at S-band were designed and fabricated and currently similar arrays are being built at C-band.