Microstrip patch back radiation reduction using metamaterial superstrate

The capability of the capacitively loaded loop (CLL) metamaterial (MTM) superstrate to attenuate surface waves thereby reducing the back radiation of microstrip patch antennas is examined. To understand the surface wave suppression mechanism, theoretical approaches of a grounded dielectric slab waveguide is provided. Both theoretical and numerical analyses show that the proposed superstrate causes a drastic attenuation of surface wave propagation. To confirm the numerical simulations, the proposed antenna is fabricated and tested. The dimensions of the CLL-MTM covered patch antenna are 0.6λ × 0.8λ × 0.14λ. The radiated gain and efficiency are measured at 7.8 dB and 95%, respectively. Measurements show that the front-to-back ratio is enhanced by more than 12 dB. In comparison with the patch antenna without the CLL-MTM superstrate, the proposed antenna reduces the gain and efficiency by less than 0.1 dB and 2%, respectively.

[1]  M. Kamyab,et al.  Artificial Magnetic Conductor Loaded Monopole Antenna , 2010, IEEE Antennas and Wireless Propagation Letters.

[2]  Y. Rahmat-Samii,et al.  Bandwidth determination for soft and hard ground planes by spectral FDTD: a unified approach in visible and surface wave regions , 2005, IEEE Transactions on Antennas and Propagation.

[3]  Wideband Miniaturized Polarization-Dependent HIS Incorporating Metamaterials , 2010, IEEE Antennas and Wireless Propagation Letters.

[4]  N. Alexopoulos,et al.  Gain enhancement methods for printed circuit antennas through multiple superstrates , 1987 .

[5]  Front-to-Back Ratio Improvement of a Microstrip Patch Antenna Loaded with Soft Surface Structure in a Partially Removed Ground Plane , 2012 .

[6]  E. Li,et al.  A Unique Extraction of Metamaterial Parameters Based on Kramers–Kronig Relationship , 2010, IEEE Transactions on Microwave Theory and Techniques.

[7]  S. Ornes.  Metamaterials , 2013, Proceedings of the National Academy of Sciences.

[8]  Eva Rajo-Iglesias,et al.  BACK RADIATION REDUCTION IN PATCH ANTENNAS USING PLANAR SOFT SURFACES , 2009 .

[9]  A. Jafargholi,et al.  Miniaturisation of printed slot antennas using artificial magnetic conductors , 2018 .

[10]  S. S. Stuchly,et al.  Analysis of a Microstrip Covered with a Lossy Dielectric , 1980 .

[11]  D. Werner,et al.  A Low-Profile High-Gain Substrate-Integrated Waveguide Slot Antenna Enabled by an Ultrathin Anisotropic Zero-Index Metamaterial Coating , 2014, IEEE Transactions on Antennas and Propagation.

[12]  L. Shafai,et al.  Investigation Into the Effects of the Patch-Type FSS Superstrate on the High-Gain Cavity Resonance Antenna Design , 2010, IEEE Transactions on Antennas and Propagation.

[13]  D. Sievenpiper,et al.  High-impedance electromagnetic surfaces with a forbidden frequency band , 1999 .

[14]  Nicolaos G. Alexopoulos,et al.  Fundamental superstrate (cover) effects on printed circuit antennas , 1984 .

[15]  Nicolaos G. Alexopoulos,et al.  Gain enhancement methods for printed circuit antennas , 1984 .

[16]  Jin Au Kong,et al.  Robust method to retrieve the constitutive effective parameters of metamaterials. , 2004, Physical review. E, Statistical, nonlinear, and soft matter physics.

[17]  Xianming Qing,et al.  A High Gain Antenna With an Optimized Metamaterial Inspired Superstrate , 2012, IEEE Transactions on Antennas and Propagation.

[18]  O.M. Ramahi,et al.  Enhanced-Gain Microstrip Antenna Using Engineered Magnetic Superstrates , 2009, IEEE Antennas and Wireless Propagation Letters.

[19]  A. O. Karilainen,et al.  Choosing Dielectric or Magnetic Material to Optimize the Bandwidth of Miniaturized Resonant Antennas , 2009, IEEE Transactions on Antennas and Propagation.

[20]  Amir Jafargholi,et al.  Mutual Coupling Reduction in an Array of Patch Antennas Using CLL Metamaterial Superstrate for MIMO Applications , 2019, IEEE Transactions on Antennas and Propagation.