Bandpass filters using stepped impedance resonators and stub loads for wide harmonics suppression

This paper proposes design of a bandpass filter with wide harmonics suppression more than 4f₀. Designing uses step-impedance resonators structure for operates the center frequency and uses stub loads for harmonics suppression. This bandpass filter is designed for support WLAN at 2.45 GHz. The measured results of the proposed bandpass filter have the insertion loss 1.00 dB and the return loss 29.26 dB at the center frequency 2.44 GHz. The harmonics suppression can be suppressed the insertion loss lower than -16 dB up to 10 GHz.