Varactor-loaded transmission-line phase shifter at C-band using lumped elements

• Published in: IEEE transactions on microwave theory and techniques Vol. 51; no. 4; pp. 1135 - 1140
• Main Authors: Ellinger, F., Jackel, H., Bachtold, W.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.04.2003; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Adjustable; Circuits; Electric potential; Frequency measurement; Frequency ranges; Gallium arsenide; Gallium arsenides; Loss measurement; MMICs; Phase control; Phase shifters; Propagation losses; Topology; Transmission lines; Transmission loss; Voltage control
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2003.809670

The design of varactor-loaded transmission-line phase shifters using lumped elements is discussed in this paper. A monolithic-microwave integrated-circuit (MMIC) phase shifter is fabricated to verify the proposed topology. Only one control voltage is required for phase control. Within a continuously adjustable phase-control range of 360/spl deg/ and a frequency range from 5 to 6 GHz, a low transmission loss of 4 dB/spl plusmn/1.7 dB is measured. The phase shifter is realized with a commercial 0.6-/spl mu/m GaAs MESFET process and requires a chip area of only 0.8 mm/sup 2/. To the knowledge of the authors, the best results reported to date are reached for a continuously adjustable passive phase shifter with comparable circuit size. The presented circuit is well suited to wireless adaptive antenna transceivers, operating in accordance with the 802.11a, high-performance radio local-area-network and high-speed wireless-access-network type-a standard.