Microstrip array antenna for multiband operation

A novel design of corporate fed four element rectangular microstrip array antenna (FRMAA) has been proposed for triple band operation at X-band frequency. By increasing the number of array elements from four to eight, the triple band operation can be converted into dual bands. This overall impedance bandwidth is 1.16 times more than the impedance bandwidth of FRMAA with improved broadside radiation characteristics. The dual-frequency patch antennas may provide an alternative to large-bandwidth planar antennas, in applications in which large bandwidth is really needed for operating at two separate transmit-receiver bands. When the two operating frequencies are far apart, a dual-frequency patch structure can be conceived to avoid the use of separate antennas. The design concept of antennas is presented and experimental results are discussed.