PURPOSE: A low pass filter for superhigh frequency is provided to enhance low-pass damping property of the low pass filter and spurious property in an associated system by using a radial stub which has a capacitance higher than a general open stub. CONSTITUTION: A low pass filter includes parallel capacitances connected to an open stub and serial inductances connected to transmission lines. The low pass filter also includes a fan-shaped microstrip line pattern(10) for realizing the parallel capacitances and a linear microstrip line pattern(20) for realizing the serial inductances. A width and a length of the transmission line and an angle and a radius of the fan-shaped stub can be calculated by the capacitance and inductance values defined by the microstrip transmission line. The low-pass filter designed by using the radial stub shows a wider low band area and a deeper damping.
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