AN ONLINE BROAD-BAND HIGH POWER RADIO FREQUENCY MATCHING DEVICE FOR ANTENNA AND ITS METHOD

摘要

The present invention relates to an online, broad-band and high power radio frequency (RF) matching device for antenna consists of at least two stubs in double stub configuration, each stub consisting of at least two transmission lines. One with fixed length line having low characteristics impedance about 16 ohm and other with variable length terminating by reflecting termination. These two lines are joined by a suitable adapter. The fixed length line comprises a strip line or a rectangular line partially or completely filled with slotted ferrite. The fixed length line consisting of an inner conductor with at least one slot and an outer conductor enclosing the inner conductor. The outer conductor may have at lest two metals preferably of stainless steel and copper. The method for matching the impedance is achieved by changing flux of the external electromagnetic field is provided to fixed length line filled with slotted ferrite. The said flux changes the relative permeability of the slotted ferrite which results in change in reactance of fixed length line. As matching is achieved just by changing electromagnet current, very low response time of order of 5-6 msec, can be achieved. By changing the length of variable length line, the reactance range offered by of variable length line changes, thereby enabling impedance matching for the range of frequency from 22 MHz to 91.5 MHz.