Microstrip couplers are widely used in microwave applications, such as antenna feeds, modulators, phase shifters, and so forth. Microstrip couplers are passive microwave components used for power division and those may have three ports, four ports, or more. Therefore, these devices are very important in microwave systems and very difficult to design. These couplers can be grouped under two main categories; backward-wave and forward-wave types. Since microstrip structures are inhomogeneous,the velocities of the even and odd modes for a coupled pair of microstrip lines are not equal resulting in poor directivity.Various compensation techniques have been reported to improve the directivity. One of these techniques is wiggly line coupler. Two choices for extending the bandwidth coupler will either be the uniform multi-section line coupler or the nonuniform line coupler. The design of multi-section line coupler is simple, however; the sharp discontinuities between various sections degrade the coupler performance. The nonuniform line coupler yields better performance because of smooth tapering along the structure. In the microstrip coupled lines, it is difficult to obtain tight coupling between lines because they require a very small spacing between them. Therefore, branch-line couplers, lange couplers, tandem couplersand multilayered configurations can be used to obtain tight coupling. In this thesis, a -3 dB nonuniform wiggly line couplerwith interdigitated and tandem configuration and a -10 dB nonuniform wiggly line coupler are designed over frequencyrange of 1-20 GHz. Key Words : Coupler, Ultrawideband, Nonuniform, Interdigitated, Wiggly lines, Lange, Tandem coupler