Title :
Triangular Ring Antennas for Dual-Frequency Dual-Polarization or Circular-Polarization Operations
Author :
Tao Zhang ; Yan Zhang ; Wei Hong ; Ke Wu
Author_Institution :
State Key Lab. of Millimeter Waves, Southeast Univ., Nanjing, China
Abstract :
In this letter, triangular ring (TRG) antennas are proposed for dual-frequency dual-polarization (DFDP) and circular-polarization (CP) operations. By simultaneously exciting the two orthogonal modes of the TRG, the DFDP or CP performance is achieved. By varying the vertex angle of the TRG, the frequency ratio (FR) of the two orthogonal modes could be continuously tunable for the DFDP operation. By moving the FR close to 1, a CP antenna element is developed for the sequential-rotation array. Due to the geometry advantage of the TRG, the array could be designed to have a low sidelobe level (SLL). Measured results show that an overlapped bandwidth (of return loss, axial ratio, and gain) of 10% and an SLL of below -20 dB are achieved. The fabricated 120 ° TRG (for the DFDP operation) and the 75 ° TRG (for the CP operation) are 28.2% and 65.5% the size of the conventional equilateral triangular patch antenna, respectively.
Keywords :
electromagnetic wave polarisation; multifrequency antennas; CP antenna element; DFDP operations; FR; SLL; TRG antennas; circular-polarization operations; dual-frequency dual-polarization operations; equilateral triangular patch antenna; frequency ratio; orthogonal modes; sequential-rotation array; sidelobe level; triangular ring antennas; Antenna measurements; Arrays; Gain; Loss measurement; Microstrip antennas; Circular polarization; dual frequency; sequential rotation; sidelobe level; triangular ring;
Journal_Title :
Antennas and Wireless Propagation Letters, IEEE
DOI :
10.1109/LAWP.2014.2319455