PBG Structure And It's Applications To Microwave Circuit

PBG is a kind of periodical structure that can realize Photonic Band-Gap. The concept of Photonic Crystals was initially proposed in the optical regime. With the development of the research on Photonic Crystals, a PBG phenomenon has been applied in the microwave and millimeter-wave domains. PBG structure is simply made, small in size, light in weight, and easily integrated in microwave band, which is not surpassed by other apparatus.This paper presents PBG structure for microwave circuit application. The effect of the structure parameters on the band-gap character of 1-D and 2-D PBG structure is discussed. An improved PBG lattice derivated from square lattice on a microstrip patch antenna is proposed. Square, square ring, circle and circle ring slots are investigated on the ground of patch antenna. The simulation and comparison are made on the patch antenna. The microstrip patch antenna with PBG structure is suggested that it can suppress the higher harmonics availably and improve the performance of the antenna. In addition, a multilayer Photonic Band-Gap (PBG) structure is studied in this paper. The planar periodic array constructed with metal units is settled between two mediums, which provides the convenience of the depth and width adjustment of the band-gap by means of altering the position of periodic array plate as well as the size and shape of metal units. The structure can be easily integrated and made without requirement of drilling in the substrate. As one of its practical applications, this structure is used to interdigital band-pass filter. Dramatic 20 dB suppression of spurious pass-band is observed.