Title :
A new structure for reflection-type phase shifter with 360° phase control range
Author :
Bulja, Senad ; Mirshekar-Syahkal, Dariush
Author_Institution :
Dept. of Electron. Syst. Eng., Essex Univ., Colchester, UK
Abstract :
A novel 360° reflection type phase shifter is proposed. It comprises a 3-dB coupler, resonant circuits, transistors and PIN diodes. The control of phase is enabled by controlling the capacitance of the varactor (transistor). The new structure provides a full 360° phase shift and it is believed that it can be extended to phase shifts even beyond 360°. Equations are derived to precisely describe the behavior of the reflective load, the range of obtainable phase shifts as well as the limitations imposed by such a structure. In one case it is shown that with a careful choice of the varactor the transmission losses can be kept to lower than 2.6 dB. Also, in another case the phase control range of 360° is obtained using a bipolar transistor with a capacitance ratio (cmax/cmin ) of only 1.28.
Keywords :
bipolar transistor circuits; phase control; phase shifters; varactors; bipolar transistor; capacitance ratio; phase control; phase shifts; reflection-type phase shifter; varactor capacitance; Bipolar transistors; Capacitance; Coupling circuits; Equations; Phase control; Phase shifters; Propagation losses; RLC circuits; Reflection; Varactors;
Conference_Titel :
Microwave Conference, 2005 European
Print_ISBN :
2-9600551-2-8
DOI :
10.1109/EUMC.2005.1610372