Patent ID: 6288677
Filing Date: 2001-09-11
Classification: H01Q

Abstract:
A method for a microstrip feeder structure for a microstrip antenna array, said microstrip antenna array having a plurality of radiating elements and an antenna operating frequency, each of said radiating elements having a radiation resistance at resonance, said method comprising:providing first and second microstrip feed lines for connecting to each of said radiating elements, said first and second feed lines each having an electrical length of approximately one-quarter wavelength at said antenna operating frequency, said first and second feed lines having identical characteristic impedances equal to a first characteristic impedance;providing a third microstrip section in series with said first microstrip feed line;selecting a length of said third microstrip section to provide a ninety-degree phase shift;selecting said third microstrip section to provide a third characteristic impedance equal to the impedance looking into said first feed line toward a respective one of said plurality of radiating elements; andconnecting an end of said third microstrip section and an end of said second microstip section together to form a first joint.