Matching network design for a double band PIFA antenna via simplified real frequency technique

This paper uses simplified real frequency technique in designing the dual-frequency antenna matching network, and takes PIFA(900/1800 MHz) as example. It could expand the antenna bandwidth and reduce the return loss. By using ADS software, we can turn the lumped network into the distributed network. The results show that the frequency band increases from 11 MHz to 14 MHz, from 205 MHz to 257 MHz, increasing about 27.3% and 25.4% separately.