RF Designs and Simulations

Multi-layer Microstrip Antenna Generally impedance bandwidth of patch antennas varies from 2-3% for single layer direct coupling or probe coupling  and can be further enhanced by coupling the power from the strip line through an aperture (slot) in the ground plane and/or printing patch effectively on the foam material whose dielectric constant is nearly equal to that of air [. In such case the feed network is isolated from the radiating element by a ground plane, which prevents spurious radiation. The resonant or non-resonant slot couples energy from the stripline to the patch. If slot is resonant, it provides another resonance in addition to the patch resonance, resulting in an antenna with 10-15% impedance bandwidth. However, the resonant slot has strong backlobe, which substantially reduces the gain of the antenna. Non-resonant slot has better front to back ratio, which results in improvement in efficiency with narrow bandwidth. Hence multilayer microstrip antennas are diffic