Microstrip bandstop filter using G-shaped defected microstrip structure

In recent years, many scholars have used defected microstrip structure (DMS) to design the notch fllter, which has similar characteristics to DGS, such as the properties of slow-wave, rejecting microwaves in certain frequencies and decreasing the size of the microstrip fllter. This paper proposes a microstrip bandstop fllter based on G-shaped defected microstrip structure (DMS) and further analysis the equivalent lumped circuit of G-shaped DMS and investigates resonant frequencies and the insertion loss changes with the parameters of G-shaped DMS. The main advantages of the proposed dual-band bandstop fllter can be adjusted to required frequency band by changing the parameters of G-shaped DMS. The design parameters of the fllter is optimized by 3D EM commercial software HFSS 13.0, and the equivalent lumped circuit of G-shaped DMS is optimized by ADS 2013, and the simulation results indicated the proposed fllter can generate two notch bands at 5.2GHz and 9.9GHz with the insertion loss less than -26dB. The new microstrip bandstop fllters based on G-shaped DMS has advantages of low loss, miniature size and simple topology. The proposed microstrip bandstop fllters based on G-shaped DMS can efficiently fllter out interfering signals in WLAN band and X band with application prospects.