The authors describe the fundamental characteristics of miniaturized hairpin resonators having parallel coupled lines and show their applications to bandpass filters and receiver front-end microwave integrated circuits (MICs). A method for calculating filter coupling parameters using a general-purpose microwave circuit simulator is presented. The bandpass filters have a suitable structure for MICs, and their size is one-half that of conventional hairpin resonators without increasing insertion losses. Trial receiver front-end MICs using these filters have been developed and have shown good characteristics such as low noise and a high image suppression ratio. They are applicable to a frequency range above the L-band.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>