Classical quarter-wave segments of UHF microstrip transmission lines are characterized by significant dimensions. To reduce them, the segments are replaced by the modified stubs, implemented based on typical topologies. The aim of the paper is to compare the frequency characteristics and efficiency of three topologies used in modified stubs with the same wave resistances and substrates, provided that they operate at the same frequency. With the use of electrodynamic modeling, the frequency properties of the modified microstrip stubs based on T- and U-shaped sections are optimized and studied. The optimization consists in providing a 50-Ω wave resistance and a minimum reflection coefficient at the operating frequency. The dimensions of the optimized modified stubs are introduced. The amplitude- and phase-frequency characteristics of the generated stubs are presented and compared. It is confirmed that the requirements for broadbandness and the greatest size minimization contradict with each other. It is established that the optimized stubs can have a length that is 23–42% less than a quarter-wave segment. In this case, the relative pass band of the stub narrows to 30–90%. The results obtained indicate the possibility of using such stubs to minimize the size of a number of microwave devices and allow making a reasonable choice of a specific topology. #CSOC1120.