Quad-Band Inverted-F Antenna System Tuned by Hybrid C-Tuner

A quad-band inverted-F antenna (IFA) system tuned by two dual voltage handling class aperture tuning networks is presented in this paper. Each of the two aperture tuners comprises a monolithically integrated hybrid C-Tuner in parallel with an off-chip high-Q inductor. The C-Tuner fabricated in a dedicated CMOS RF switch-technology fulfils the requirements for both mid- and high-voltage handling classes and can be brought to the required voltage class on the application level. The C-tuner is configured to 371 fF – 1.8 pF and 80 V RF voltage range when attached to the open end of the antenna and to 668 fF – 6 pF and 40 V RF voltage range when connected close to the feed point. The measured quad-band IFA covers cellular low-, low-mid, mid- and high-bands with the 6 dB return loss at the feed over the 85 % of the whole target frequency range.