Dual band port isolation enhancement between microstrip array elements

This paper presents a new technique to improve the port isolation between two closely spaced dual band patch antenna elements using shunt frequency dependent reactive impedances. A compact two element dual band microstrip antenna array is designed to operate for Bluetooth at 2.45 GHz and WIMAX at 3.5 GHz applications. The proposed approach utilizes two edge coupled transmission lines after inserting a transmission line adjusted to convert trans-admittance between input ports to a pure positive and negative imaginary values at the lower and higher frequencies respectively. Measurement results show an isolation enhanced by 29 dB and 24 dB at 2.45 GHz and 3.5 GHz respectively. The proposed technique shrinks the space between the two elements to be λ0/10 at 3.5 GHz. The design has been simulated and validated experimentally.

[1]  M. Kanagasabai,et al.  Implementation of Slotted Meander-Line Resonators for Isolation Enhancement in Microstrip Patch Antenna Arrays , 2013, IEEE Antennas and Wireless Propagation Letters.

[2]  Shyh-Jong Chung,et al.  A Decoupling Technique for Increasing the Port Isolation Between Two Strongly Coupled Antennas , 2008, IEEE Transactions on Antennas and Propagation.

[3]  D. Pozar.  Microwave Engineering , 1990 .

[4]  A. Ludwig.  Mutual coupling, gain and directivity of an array of two identical antennas , 1976 .

[5]  Eva Rajo-Iglesias,et al.  Mutual Coupling Reduction in Patch Antenna Arrays by Using a Planar EBG Structure and a Multilayer , 2008 .

[6]  Malathi Kanagasabai,et al.  Deployment of Modified Serpentine Structure for Mutual Coupling Reduction in MIMO Antennas , 2014, IEEE Antennas and Wireless Propagation Letters.

[7]  J. Nourinia,et al.  A rectangular defected ground structure (DGS) for reduction of mutual coupling between closely-spaced microstrip antennas , 2012, 20th Iranian Conference on Electrical Engineering (ICEE2012).

[8]  H. S. Farahani,et al.  Mutual Coupling Reduction in Patch Antenna Arrays Using a UC-EBG Superstrate , 2010, IEEE Antennas and Wireless Propagation Letters.

[9]  Ramesh Garg,et al.  Reduction of mutual coupling between closely spaced PIFAs , 2010 .

[10]  Seong-Ook Park,et al.  Compact Antenna Array With Port Decoupling for LTE-Standardized Mobile Phones , 2009, IEEE Antennas and Wireless Propagation Letters.

[11]  Manuel Sierra Castañer,et al.  New EBG solutions for mutual coupling reduction , 2012 .

[12]  O. Quevedo-Teruel,et al.  Mutual Coupling Reduction in Patch Antenna Arrays by Using a Planar EBG Structure and a Multilayer Dielectric Substrate , 2008, IEEE Transactions on Antennas and Propagation.