Planar dipole antenna loaded with bandstop reflector

A planar dipole antenna loaded with bandstop reflector is presented and investigated. The loading structure is composed of two symmetrically positioned twin lines. The loading structure acts as a bandstop filter in the corresponding frequency band, and meanwhile functions as a reflector in the operating frequency band, which is not a combination but an integration of reflector and bandstop filter. Measured results show that the realized gain of the loaded planar dipole antenna is 5.1 dBi for the allocated operating frequency and -23 dBi for the stopband frequency. This antenna can be used for rejection of image frequency or local oscillator frequency in superheterodyne architecture.