Investigation of the Connection of Additional Stubs to the Phase Shifter Based on the Directional Coupler

The 3-position phase shifter with arbitrary phase shifts is suggested. The phase shifter consists of the branch-line quadrature coupler with two switched by p-i-n diodes stubs in each of two arms. The main difference of the proposed technical solution is that in the presence of two stubs we realized three phase shifts instead of two as usual. The different phase shift can be realized by selecting the appropriate length of lines and stubs. Their value is determined by solving a system of transcendental equations. Simple formulas for initial estimates of the elements size of the phase shifter are given. Computer simulations were performed with NI-AWR Design Environment software. The frequency dependence of the scattering matrix elements is shown. The suggested phase shifter showed good stability and linearity of the phase shift with frequency change. After modeling, the model of the phase shifter was manufactured and its frequency characteristics were measured. A good agreement between the calculated and measured characteristics is noted.