Modification in microstrip low pass filter using bulb shape patch

This paper presents bulb type semicircular microstrip low pass filter with the sharp rejection and wide stop band. The proposed design is based on the calculation of parameters from traditional high–low impedance method and is available in the literature of microstrip filter. To further improve the design performance, high impedance lines are magnetically coupled, resulting an attenuation pole near −3 dB cut off point of the filter. This design gives insight in designing a low pass filter with reduced size with an arbitrary geographical shape.