Effects of curvature on the fabrication of wraparound antennas

The extension of the microstrip antenna design from planar to cylindrical structures introduces a variety of complications, both in the modeling and fabrication of the structures. Parametric variations due to curvature can be determined theoretically, but it has been found that the process of shaping planar microwave materials into cylinders can cause significant changes to their electrical and physical properties which must be taken into account when designing antenna elements and feed circuitry. The material issues that arise during fabrication of conformal microstrip antennas are discussed in this paper. Several cylindrical microstrip patch antennas were designed using Boulder Microwave Technologies Clementine (R) software. Allowances for the changes that occur in the material as a result of formation were included both as adjustments to the material parameters input into the program, and to the dimensions of the resulting designs. These designs were then fabricated and measured for comparison with simulated results.