A Broad-Band Element for Microstrip Bias or Tuning Circuits (Short Papers)

A microstrip radial transmission line circuit element namely a 180/spl deg/ circular stub or "half-moon" structure, having a reflection coefficient of unity magnitude and phase which varies slowly with frequency is presented. Theoretical reflection coefficient data are shown to agree well with experimental microstrip (epsilon/sub r/=2.35, h =250 mu m) data in X band. Applications of the half-moon microstrip element in the design of broad-band bias or tuning networks are discussed.