Double‐slot‐fed microstrip antennas for circular polarization operation

Abstract

Using the cavity model theory, simple design formulas are developed for double‐slot‐fed circularly polarized microstrip antennas. Equivalent magnetic current sources are assumed at the slot positions and then the electric field distribution under the patch is obtained in terms of cavity modes. By applying the circular polarization conditions to the far‐field components of the electric field, the loci of the positions of the slots for the circular polarization operations are found. Experimental results are successfully demonstrated based on the theoretical designs.

Low-Cost Broadband Circularly Polarized Printed Antennas and Array

“…The characteristics of a cross-slot-coupled patch antenna have been reported in [8,9]. By using a crossed slot to couple the electromagnetic energy from the microstrip feed to the radiating element, circularly polarized radiation can be easily obtained.…”

“…Compared to the conventional niricrostrip or probe-fed antenna, the aperture-coupled feed has numerous advantages, such as isolation of the feed from the radiating element, easy integration with the active RE/microwave circuits, etc. For the circularly polarized antenna, a dual-feed network is widely used to excite the two orthogonal modes (TM 01 and TM 10 ), which can then be combined to achieve circularly polarized radiation by inserting a 90' phase- shifter circuit between the two feeds [8,9]. However, this dualfeed technique results in a complicated antenna structure and higher cost, in particular when stacked patches are also used for achieving broadband circularly polarized operation.…”