Novel Half-Ring Microstrip Resonator

This paper presents the results of a novel half-ring microstrip resonator that behaves like an annular-ring resonator having identical resonant mode frequencies as the annular-ring, without compromising insertion loss at resonant modes. In addition, the half-ring structure has the advantage of occupying just half the size of a conventional annular resonator. The measured results show that the loaded Q-factor of the half-ring resonator does not significantly degrade when compared to the annular-ring resonator having the same mean radius and when constructed on identical dielectric substrate. The measured insertion loss of the half-ring at its fundamental resonant mode is 4.42 dB, its return-loss is 8.97 dB, and its loaded Q-factor is 78 when fabricated on dielectric substrate with ¿r=2.17 and h=0.794mm.