One of the projects we have completed a small dual polarization stacked patch array design operating in the lower part of S band.
There were several requirements:
- Low mutual coupling.
- VSWR better than 1.6:1 over the operational band.
- High gain.
In this design, the lower substrate contains the driven elements and the upper substrate contains the parasitic elements. The choice of substrate directly impacts the gain. In order to minimize dielectric losses (increasing the gain) while keeping the cost low, a Rogers RO4350B substrate was used for both substrates.
A plastic ABS Radome was placed directly on top of the upper substrate. In order to meet the bandwidth requirements, a 1 cm air gap was used over the 60 mils lower substrate.
In the end, a we achieved a worst-case bandwidth of 12.5% for a return loss less than or equal to 10 dB. The element-to-element coupling was less than -19 dB. The peak gain of a single element was greater than 7.5 dBi. This met the design goals.
ARSI 