Open AccessTunable 200 GHz lens‐coupled annular‐slot antennas using Schottky varactor diodes for all‐electronic reconfigurable terahertz circuits
Author(s) -
Jiang Z.,
Rahman S. M.,
Fay P.,
Hesler J. L.,
Liu L.
Publication year - 2013
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2013.3217
Subject(s) - varicap , capacitance , schottky diode , optoelectronics , materials science , diode , terahertz radiation , antenna (radio) , biasing , slot antenna , diffusion capacitance , optics , voltage , electrical engineering , physics , dipole antenna , engineering , electrode , quantum mechanics
A tunable lens‐coupled annular‐slot antenna using a Schottky varactor diode has been designed, fabricated and characterised at 140 to 220 GHz. Simulation results show that the resonant frequency of the annular‐slot antenna can be effectively tuned by varying the capacitance of the imbedded varactor diode, with an average tunability of ∼2.5 GHz/fF. Prototype demonstration using a varactor with zero‐bias capacitance of 3.8 fF has shown a frequency tuning range from 197 to 202.7 GHz by varying the diode DC bias voltage from 1 to −5 V (corresponding to a diode capacitance change from 4.97 to 2.4 fF). The measured tunability is 2.22 GHz/fF, which agrees well with simulation. Projections indicate tuning ranges of ∼50 GHz in the G‐band should be possible using varactor diodes with ∼20 fF zero‐bias capacitance.