Résumé | As technology advances, the requirement and need for smaller and finer phase-control for phase steps less than 2° is arising (if the demand is not here already). Unfortunately today, most phase shifters have minimal resolution of 5.625°and that has been the status quo for quite some time now. The objective of this paper's research and investigation is to show how one can implement phase shifts as low as 1.41° (or lower) for use as the phase shifter's least-significant-bit (LSB). The paper shows a design and proof-of-concept of a phase shifter at 2.1 GHz simulated on FR4 substrate using off the self surface mount device (SMD) components. The phase shifter in this paper had eight phase shifting blocks for 8-bits of resolution (control). The architecture of the eight blocks were purposely designed differently to showcase the flexibility and use of a diode loaded phase shifting trimmer as the first couple units of the phase shifter - for the smallest phase changes of 1.41°and 2.81°. Phase shifting blocks 3–4 (for 5.625°and 11.25°phase change) were designed using hybrid couplers, and blocks 5–8 (for 22.5°, 45°, 90°, and 180°phase change) were designed using T-bridge topology (since modern technology already incorporates them). The diode loaded trimmer was used for the fine tuning steps since diodes are almost always readily available in all kits, they take up low layout area, and are easy to implement. |
---|