Microstrip filters based on 2D electromagnetic crystal
Construction of microstrip bandpass filters is suggested on the basis of 2D electromagnetic crystal consisting of P horizontal and K vertical rows of resonators. Adjacent vertical rows of resonators are connected by additional m K-1 resonators arranged above and below the outside 2D crystal. Parametric synthesis of six bandpass filters based on crystals with the dimension of 1×2, 2×2, 2×3, 3×1, 3×2 and 3×3 was conducted with use of electrodynamic numerical analysis of 3D models in studied constructions. While calculating substrates with relative permittivity ε=80, h=1 mm thick were used, in this connection, center frequency of bandwidth was registered as follows - f 0≈1.0 GHz, as well as their relative bandwidth Δf/f 0≈20%. High frequency-selective properties of the filters are connected not only with the increase of their N order, but also with the presence of amplitude-frequency characteristics of power attenuation poles located near the bandwidth.