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 [1, 2]. 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 Ω 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.