Suspended patch antennas with electromagnetically coupled inverted microstrip feed for circular polarization

The paper demonstrates a suspended nearly square patch antenna with offset feed and a square patch antenna with truncated corners for circular polarization. The antennas are excited by an electromagnetically coupled inverted microstrip feed. In addition a new transition between conventional microstrip and inverted microstrip is proposed. The measured results include the axial ratio and the impedance bandwidth of the antennas.