Combined PIFA/DRA

Antenna for RF Energy Harvesting

Summary

Drawing upon existing designs for a Planar Inverted F Antenna (PIFA), operating in the GSM (900 MHz) band, and a Dielectric Resonator Antenna (DRA) operating in the upper GSM (1800 MHz) and WiFi (2.4 GHz) bands, designed and simulated a combined design overlaying these two architectures. Successfully realized isotropic gain of >6 dB average across each band. Useful for RF energy harvesting in congested and heavily used frequency bands.

Isotropic Gain

Nearly-isotropic radiation patterns with high gain

Compact Design

Small form factor design (resonator dimensions 25.2mm height x 36.4mm radius)

Single feedpoint (blue cylinder, rear) simplifies design.

Impedance Match

PIFA (top) and DRA (bottom) designed for optimal match in each of the three referenced bands.

Takeaways

Aperture coupling was found to produce the best radiation pattern for DRA, whereas PIFA benefits from probe coupling
Demonstrated feasibility of overlaying PIFA on top of and fed through DRA to capture energy in all 3 desired bands
Separate-fed design has increased complexity but offers better capture of energy in lower GSM band