Single-Unit Multibit Phase Shifters Using Binary Multibit Susceptance Blocks

A novel approach for the implementation of single-unit multibit phase shifters (SUMBPSs) using binary multibit susceptance blocks (MBSBs) is presented. A single 50- $\Omega $ main transmission line (MTL) is symmetrically loaded with three binary MBSBs, each comprising M parallel open-circuited stubs and p-i-n diodes. The linear relationship between loaded susceptance and phase shift is established by leveraging the linearity of susceptances curves w.r.t. length of the MTL. The use of single MTL allows the realization of SUMBPSs in a compact, single-unit structure with lower insertion loss (IL), whereas the linear susceptance curves enable the application of the principle of superposition, achieving the required $2^{M}$ phase states with only $3\times M$ stubs and switches, representing a significant reduction compared with other contemporary solutions. For validation, a 3-bit SUMBPS is developed, and measurement results are given.