Compact Reflection-Type Phaser Using Quarter-Wavelength Transmission   Line Resonators
  A compact reflection-type phaser composed of quarter-wavelength transmission line resonators interconnected by alternating K- and J-inverters is proposed. A design method is also presented. To validate this method, a 4th-order example is designed and fabricated. The proposed phaser is shown to exhibit the benefits of smaller size, easier fabrication and suppressed even-order harmonics compared with previously reported half-wavelength phasers. 
Weiwei Liao, Qingfeng Zhang, Yifan Chen, Christophe Caloz
physics.class-ph physics.optics