Optimization of Inkjet Printing of Patch Antennas on Low-Cost Fibrous Substrates

In this letter, the inkjet-printing procedure is used to implement microwave circuits on low-cost fibrous substrate, cardboard. As a first step for environmentally friendly electronics applications, the high-frequency properties of the cardboard substrate are extracted using the two-transmission-line method and dielectric probe measurement. To provide an accurate model for the inkjet-printed conductors, the conductivity and thickness of the printed silver traces are analyzed. The surface of the substrate is pretreated using a dielectric ink to reduce the penetration of the conductor ink into the fibrous substrate and to diminish the conductor loss at high frequencies. As a technology demonstrator, a patch antenna is printed on a cardboard substrate, and the simulation and measurement results are compared to study the reliability of the obtained parameters. After initial experimental verification, simulation models were fine-tuned in order to provide a predictive method for design and fabrication of low-cost RF circuits. The achieved model can be used to design and fabricate low-cost RF structures on fibrous environmentally friendly substrates .