Patent ID: 9666946
Date: 2017-05-30
CPC Classifications: H01Q

Claim:
1. A four element reconfigurable MIMO antenna system, comprising: a rectangular dielectric substrate having a top surface, a bottom surface, opposing short peripheral edges, and opposing long peripheral edges; first, second, third, and fourth PIFA radiating elements disposed on the top surface of the rectangular dielectric substrate, each of the PIFA radiating elements having an F-head portion of the PIFA defining two arms extending to one of the long peripheral edges of the rectangular dielectric substrate and an F-tail portion extending from one of the short peripheral edges of the rectangular dielectric substrate and having a meander pattern of conducting material extending from a bottom region of the F-tail portion, the first PIFA and second PIFA radiating elements being mirror images of each other, and the third PIFA and fourth PIFA radiating elements being mirror images of each other; a corresponding bias circuit disposed in each of the four PIFA radiating elements between the two arms of the F-head portion and the meander pattern at the bottom region of the F-tail portion, the bias circuit including: a variable voltage terminal extending from the F-tail portion below the varactor diode; whereby the PIN diode may be switched ON and OFF to lengthen or shorten electrical length of the F-tail portion and a variable voltage may be applied across the varactor diode to change electrical impedance of the F-tail portion; a feed connector connected to the F-head portion arm most distal from the short peripheral edge of the rectangular dielectric substrate of each of the PIFA radiating elements; and a ground plane for each of the PIFA radiating elements disposed on the bottom surface of the rectangular dielectric substrate.