Millimeter-wave CP-LP Reconfigurable Antennas Using PCM

In this paper, a millimeter-wave (mm-wave) circularly/linearly-polarized (CP-LP) reconfigurable antenna using phase changing material (PCM) with simple structure is proposed. It is the new attempt to apply a vacuum-filled slot excited by a substrate-integrated- waveguide (SIW) transmission line, above which a rectangular sheet is located. Circle- and linear-polarization (CP) polarization (LP) can be obtained by controlling operating states of PCM, which used to form the rectangular copper between amorphous and crystalline state. It should be mentioned that the proposed antenna yields wide impedance bandwidths when operating at two states. Besides, the proposed antenna is constructed on two PCB layers and has a simple structure, which is easy to be fabricated and low-cost. For validation, the proposed antenna is designed and simulated. The results show that, for LP state, a wide bandwidth of 58% from 55 to 100 GHz is obtained, with a peak gain of 12 dBi. For CP state, an axial ratio bandwidth of 4 GHz is obtained, with a peak gain of 8 dBic. It can be observed that the radiation patterns are stable and symmetric across the operating bandwidth. With all these features, the proposed design is attractive for mm-wave applications and wireless communication systems.