360° T-Section Digital Phase Shifter
Binboğa Sıddık Yarman · River Publishers eBooks · 2022
In Chapters 6, 7, and 8, we introduced 180° low-pass- or high-pass-based LC-T or LC-π type symmetrical digital phase shifters (DPSs) LC-π type symmetrical digital phase shifters, employing solid-state MOS or PIN diodes. Those types of phase shifters can provide phase shifts up to 90° with reasonable element values. Therefore, they are easy to implement for narrow phase range and narrow bandwidth applications. If we go beyond 90°, bandwidth significantly reduces. Moreover, it is not possible to obtain the exact 180° phase shift with the design concepts introduced in Chapters 7, 8, and 9. The lattice digital phase shifter topology (3S-DPS) presented in Chapter 10 can provide the exact 180° phase shift without any problem. It even goes up to 360° over broadband. On the other hand, the lattice structure introduced in Chapter 9 includes eight solid-state switches, which may make the physical implementation difficult. In this chapter, we introduce a different design concept to construct DPSs to cover 360° phase shift range by employing a T-section-based DPS topology introduced in Chapter 7. This structure is much simpler than that of lattice DPS. It only includes three switches. However, it provides much less bandwidth than that of lattice DPS. It should be mentioned that the content of this chapter is based on our previous work presented in the classical literature [1–3].