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 2×2 array prototype is fabricated by pressing three PCB boards together. Simulated results of the element show reflection coefficient bandwidth (|S₁₁|<;-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 24~32 GHz. The gain fluctuates less than 1.6 dB within the same band. The height of the antenna is 0.21λ₀ (λ₀ is the free space wavelength of the center frequency).