Design of printed X-band patch antenna arrays with switched line phase shifters

Microstrip phased array antennas printed on flexible substrates have broad applications in radar, aerospace, point-to-point communications, operations (e.g., RFID) and health monitoring. We report on the design, fabrication and characterization of 1×2 and 1×4 microstrip arrays operating at 10 GHz. The radiation characteristics of the arrays were simulated as a function of bending radius for three different bending configurations: concave, convex and longitudinal concave. Simulations examine the impact of bending radius and the number of radiating elements on performance compared to the planar case. As the number of radiating elements increases, the mutual coupling between patch antennas plays a vital role in the performance of the arrays. The results indicate that there is not a significant degradation in array performance until the substrate bending radius is below 20. As shown in Fig. 1(f) and 1(g), for extreme bending (e.g.,), significantly shifts to lower frequency whereas for longitudinal concave these shift observed lower compare to others. Also, for longitudinal concave arrays, the half power beam width (HPBW) remains almost unchanged though extreme bending of the substrate occurs (e.g.,). Finally, antenna arrays were optimized and simple switched line phase shifters were designed and implemented to steer the beam. Moreover, phase compensation for these antennas, when conformed, are analyzed. Antennas were fabricated using an additive manufacturing printing technique (aerosol jet) on Kapton substrates. In addition, the design of phase shifting elements in the arrays will be discussed as well as and designs of different feed structures. The details of the printing techniques for the array with details on the material selection and phase shifters will be provided.