Disclosed is a high-temperature superconductor low-pass filter for removing
broadband harmonics in a wireless communication system. The
high-temperature superconductor low-pass filter includes a coupled line
section and a transmission line section, in which the coupled line section
is connected in parallel with the transmission line section. The coupled
line section has two microstrip open-stub type parallel stripe lines
stacked on a high-temperature superconductor, and the transmission line
section has one stripe line. Since the high-temperature superconductor
low-pass filter has attenuation poles at a stopband, it has stopband
characteristics to 7-8 times wider than a cutoff frequency. The
high-temperature superconductor low-pass filter can easily remove
sub-harmonics which are inevitably occurred in the wireless communication
system.