The design of nine element quasi microstrip log periodic antenna

This paper described the design, simulation and fabrication of the inset feed log periodic antenna with nine elements. The antennas have been modeled using microstrip lines and S parameter data from an individual single element. The data is extracted from the simulation and combined with the microstrip transmission line. The properties of antennas such as bandwidth, gain, cross-polar isolation and half power beamwidth have been investigated and compared between simulation and measurements. A bandwidth up to 51% is achieved by using nine-element arrays. The cross-polar isolation of the log periodic antenna is in the range of 10 to 30 dB. The typical half power beamwidth (HPBW) of the log periodic antenna is 40° for E plane and 60° for H plane. The gain of the antenna relative to the dipole antenna ranges from -3 dB to 5 dB.