Coupled‐line Proximity‐coupled Microstrip Linear Array Antenna for Millimetre‐wave Applications

A novel low-cost, millimetre-wave antenna has been presented in this communication. The proposed antenna is a proximity-coupled linear array with coupled feedlines to achieve wideband characteristics. Good agreement between simulated and measured results is achieved and proves that the proposed antenna structure is capable of attaining over twice the bandwidth with the coupled lines than that attained with a single microstrip feedline while achieving lower sidelobe levels. The antenna has a gain of about 15.0 dBi with an half-power beam width of 12 degrees +/- 2 degrees over a frequency range of 27.25-29.25 GHz. It also exhibits an impedance bandwidth of 19.6% from 24.48 to 29.8 GHz.