A new type of microstrip low-pass filter

In this paper, a novel microstrip is proposed. A microstrip line on both sides connecting a short 50 ohm microstrip line as the main line. Such microstrip line not only has the certain characteristic of the ladder impedance, but also has some of its own features. Then you can effectively reduce the size of the microstrip. In this structure as a basic, add microstrip stubs on the microstrip line to suppress the return loss of the passband. While increasing the defected ground structure (DGS), in order to enhance the suppression of the resistance band insertion loss. In this paper, the size of proposed structure is 26mm × 15mm, the passband is 0 ∼ 2.73GHz. The insertion loss is less than 0.2dB and the return loss is greater than 10dB. The insertion loss of resistance band from 3.45GHz ∼ 16.5GHz is greater than 20dbB. The insertion loss from 4GHz ∼ 16.5GHz is greater than 35dB, mostly return loss from 3GHZ ∼ 16.5GHz is less than 0.3dB.