Cavity backed hi-lo stacked patch antennas

At previous symposia we have introduced edge-fed cavity backed patch antennas as an alternative to a conventional edge-fed configuration that overcomes several of the inherent issues associated with this architecture (W. S. T. Rowe et al., July 2006 and A. S. Elmezughi, et al., June 2007). We have shown both theoretically and experimentally that this dielectric filled cavity backed radiator has significantly higher efficiency and less pattern scalping than a traditional edge-fed patch for two reasons: (i) the cavity reduces the amount of surface wave propagation; and (ii) the thin substrate layer used to etch the feed network allows for a thinner track width to realize a 50 Omega characteristic impedance, and therefore reduces spurious radiation from the feed network. The new cavity backed edge-fed radiator shows a 3 dB improvement in the gain, and reduces the pattern undulation by 10 dB. The attributes of this architecture are particularly suited to large planar arrays, which is a prevalent application of edge-fed microstrip patches.