Method of producing a quadrifilar antenna and antenna according to this method

摘要

In a method of producing a quadrifilar antenna for circularly polarised radiation at frequencies above 200 MHz, the antenna is tuned by coupling it to a test source, measuring the relative phases and amplitudes of currents at predetermined positions in the individual elements of the antenna by means of probes capacitively coupled to the elements, and laser etching apertures (26A - 26D) in the elements to increase their inductance, the sizes of the apertures being computed according to the deviation of the measured relative phases from predetermined values.