A novel ultra-wideband (UWB) bandpass filter (BPF) with a fractional bandwidth (FBW) of about % 110 is presented using the hybrid microstrip-defected-ground structure (DGS). The proposed filter was designed using a combination of hybrid microstrip-defected-ground structure lowpass filter (LPF) with typical quarter-wavelength short-circuited stubs highpass filter (HPF), followed by an optimizati...

A stepped impedance resonator (SIR) based wideband bandpass filter (BPF) with a good rejection level in the extended upper stopband is presented in this article. The proposed SIR is found to have the ability to introduce two transmission poles in the passband. By appropriately selecting the impedance ratio and length ratio (α) of the SIRs, the BPF can provide a wide passband and a sharp rejecti...

This paper addresses a modified bandpass ring resonator filter providing compact size, low insertion-loss, wide bandwidth, sharp rejection and suppressed higher order modes. The filter enhancement follows a threefold approach. First, UC-PBG structures are used to suppress the higher order passbands yielding an upper stopband that reaches 4.7 GHz, beside offering a further advantage in terms of ...