A Novel Compact Tri-Band Impedance Matching Network with Enhanced Frequency Ratios

In this paper, a novel design of a tri-band impedance matching network has been reported. The specialty of the design lies in its compact size and its ability to operate at elevated frequency ratios, extending 7.5 and beyond. A newly introduced concept of a common frequency has been used. The core of the proposed design consists of a cascade of two L-section dual band transformers. Linking between them for tri-band operation, has been done using the concept of a common frequency. A prototype has been fabricated on RO5880 substrate and tested at the three commercial frequencies of 1.8 GHz (GSM), 2.4 GHz (WiFi/Bluetooth) and 5.8 GHz (WiFi LTE). The measured results are in good agreement with the simulations.