A Wideband Planar Array Antenna for Ka-Band Wireless Communication Applications

A wideband planar array antenna is proposed for Ka-band wireless communication applications in this paper. It consists of several rectangular radiating cavities and a stripline feeding network. Metalized posts are employed to improve the impedance matching. Besides, higher harmonic mode can be suppressed by these metalized posts. A transition from a standard waveguide to a strip line is designed based on the same method. Finally, a 2x2 array prototype is fabricated by pressing three PCB boards together. Simulated results of the element show reflection coefficient bandwidth (vertical bar S-11 vertical bar<-10dB) of 46.6% and gain more than 5dBi ranging from 23GHz to 37 GHz. Measured results of the array demonstrate more than 20% of reflection coefficient bandwidth within the frequency band of 24 similar to 32 GHz. The gain fluctuates less than 1.6 dB within the same band. The height of the antenna is 0.21 lambda(0) (lambda(0) is the free space wavelength of the center frequency).