摘要 |
A quadrifilar antenna for use in satellite communications comprises four conductive elements arranged to define two separate helical pairs, one slightly differing in electrical length than the other, defined by a cylinder of constant radius supported by itself or by a cylindrical non-conductive substrate. The two separate helical pairs are connected to each other in such a way as to constitute the impedance matching, electrical phasing, coupling and power distribution for the antenna. In place of a conventional balun, the antenna is fed at a tap point on one of the conductive elements determined by an impedance matching network which connects the antenna to a transmission line. The matching network can be built with distributed or lumped electrical elements and can be incorporated into the design of the antenna.
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