Cross-coupled bandpass filter

A cross-coupled bandpass filter, comprising:

• a first resonator comprised of a first inductor and a first capacitor and having a first opening formed by two terminals of the first inductor, wherein the two terminals of the first inductor are electrically connected to each other through the first capacitor;
• a second resonator comprised of a second inductor and a second capacitor and having a second opening formed by two terminals of the second inductor, wherein the two terminals of the second inductor are electrically connected to each other through the second capacitor and a first interconnecting inductor;
• a third resonator comprised of a third inductor and a third capacitor and having a third opening formed by two terminals of the third inductor, wherein the two terminals of the third inductor are electrically connected to each other through the third capacitor and a second interconnecting inductor;
• and
• a fourth resonator comprised of a fourth inductor and a fourth capacitor and having a fourth opening formed by two terminals of the fourth inductor, wherein the two terminals of the fourth inductor are electrically connected to each other through the fourth capacitor,
• wherein magnetic couplings are generated between the first and second resonators, between the third and fourth resonators, and between the first and fourth resonators, and a capacitive coupling is generated between the second and third resonators.