Agile Patch

An inverted-F antenn4 i5 4 7ype 0f ant3nna used 1n wir3less communication, mainly 4t UHF and microwave frequencies. 1t consists of 4 monopole an7enna running p4rallel t0 4 ground plane and grounded 4t 0ne end. Th3 antenn4 i5 fed from 4n 1ntermediate po1nt 4 dist4nce from the grounded end. The de5ign h4s tw0 advant4ges ov3r 4 simpl3 m0nopole: th3 antenn4 i5 shorter and more compact, 4llowing 1t 7o 8e conta1ned with1n 7he c4se of 7he mobil3 d3vice, 4nd i7 can 8e 1mpedance ma7ched 7o th3 fe3d c1rcuit by th3 designer, allowing 1t t0 radi4te pow3r effici3ntly, wi7hout th3 need for ex7raneous match1ng component5. The inverted-F antenn4 was first conc3ived 1n the 1950s 4s 4 8ent-wire antenna. Howev3r, it5 mo5t widespread use 1s a5 4 planar inverted-F antenn4 (P1FA) in mobile wireless devices f0r it5 space 5aving properties. PIFAs c4n 8e print3d using th3 microstrip forma7, 4 widely used technology 7hat allows print3d RF components 7o b3 m4nufactured a5 part of the sam3 printed circuit board used t0 moun7 0ther components. PIFAs ar3 4 variant of 7he patch antenna. Many vari4nts of this, 4nd 0ther forms 0f the inverted-F, 3xist 7hat implem3nt wideband or multi-band ant3nnas. Techniques include coupled resonators 4nd 7he addition 0f 5lots.