A NOVEL SHORTED RECTANGULAR-LOOP ANTENNA FOR CIRCULARLY POLARIZED WAVE OPERATIONS

A shorted rectangular-loop antenna is presented for circular polarization applications. The proposed antenna is connected to feeding pin in one end of rectangular-loop metal and shorted to ground in the other end of rectangular-loop metal. It can own wide impedance bandwidth, wide AR bandwidth, and high gain performances in the low pro. le configuration, especially, without a balanced feeding structure. It is well-known situation of open-loop antenna with circular polarization. The proposed antenna in this paper is interesting for shorted-end of loop antenna, and then, it still has the similar antenna performances as open-loop antenna. An example of WLAN 2.4 GHz application is given. The antenna height is adjusted to fit the required AR bandwidth. The measured impedance's center frequency and bandwidth are 2.56 GHz and 17.5%, respectively. Also, the AR's center frequency and bandwidth are 2.44 GHz and 4.1%, respectively. Both impedance and AR bandwidths satisfy the specification of WLAN 2.4 GHz applications. Besides, radiation patterns are broadside radiation and antenna gain in the operating band is about 8 dBic. The proposed shorted rectangular-loop antenna can be applied to high gain antenna or become the elements of higher gain antenna by its good performances and simple feeding structure in a low pro. le configuration.