A new type of phase shifter using cascaded sections of NRI metamaterials and PRI transmission lines has been proposed, which offers some significant advantages over conventional delay lines. The phase shifter is compact in size, can be easily fabricated using standard etching techniques and exhibits a linear phase response around the design frequency. It can incur either a negative or a positive phase depending on the values of the loading elements, while maintaining a short physical length. In addition, the phase incurred is independent of the length of the structure. Due to its compact, planar design, the structure lends itself easily towards integration with other microwave components and devices. It is therefore ideal for broadband applications requiring small, versatile, linear phase shifters.