An Accurate Analytical Model to Calculate the Impedance Bandwidth of a Proximity Coupled Microstrip Patch Antenna (PC-MSPA)

Abstract

This paper presents a new set of analytical equations to calculate the impedance bandwidth of electrically thin and thick proximity-coupled square microstrip patch antenna (PC-MSPA). The proposed mathematical model uses the relationship among different antenna parameters, material, and antenna dimensions to estimate the percentage impedance bandwidth with high accuracy. The proposed model was validated with rigorous full-wave solutions, and experimental antenna prototypes implemented for different thicknesses, patch dimensions, frequencies, and different substrates. The theoretical bandwidth results of S-, Cand X-band PC-MSPA antennas obtained using the new model are in very good agreement with simulations and the experimental results. Errors between the proposed analytical model and both simulation and measurement are less than 3.1%. These equations are mostly valid for permittivities between 2.2 and 6.15, and with feed substrate thickness less than 0.1λr. The PC-MSPA is a candidate element for integration with MIMIC devices and wireless communication applications.

Keywords

• Microstrip patch antenna
• proximity coupling feed
• wide bandwidth
• multi-layer structure
• non-linear curve-fitting technique