A compact suspended planar patch antenna for microwave imaging sensor array

A compact suspended planar patch antenna is presented for microwave imaging sensor array designed at ISM Band. The radiating patch of the compact suspended antenna is placed at a height of 5mm considering air dielectric substrate (ε_r = 1.001). The antenna is fed by a coaxial probe and single shorting post is placed in its lower left corner of radiating edge. More compactness is achieved by cutting a single rectangular slot at one of the radiating edges of the patch antenna, resulting in an area reduction factor of approximately equal to 20. Compact suspended planar patch antenna design equations are validated by experimental data and data obtained using MoM based EM simulator (IE3D). The proposed antenna provides resonant frequency 2.45 GHz, impedance bandwidth 3.22%, S₁₁ of-33 dB, gain of 3.9 dBi, and directivity 4.43 dBi with a high radiation efficiency of 88.7%. It is needed for microwave imaging sensor arrays. Simulated and fabricated planar patch antenna has achieved compact design by 95% size reduction compared to a conventional suspended planar patch antenna.