Open AccessA 220 GHz Orthogonal Modulator Based on Subharmonic Mixers Using Anti‐Paralleled Schottky Diodes
Author(s) -
HE Yue,
LIU Ge,
LIU Juan,
LIN Changxing,
SU Wei
Publication year - 2022
Publication title -
chinese journal of electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.267
H-Index - 25
eISSN - 2075-5597
pISSN - 1022-4653
DOI - 10.1049/cje.2021.00.270
Subject(s) - schottky diode , harmonic mixer , demodulation , physics , antiparallel (mathematics) , diode , electrical engineering , materials science , optics , optoelectronics , phase noise , local oscillator , engineering , channel (broadcasting) , quantum mechanics , magnetic field
In this paper, A 220 GHz orthogonal modulator based on two symmetrical subharmonic mixers is designed, analyzed and measured, where the mixers are implemented basde on antiparallel Schottky diodes. The orthogonal modulator consists of a 90° phase shifted 220 GHz 3 dB coupler, two sub‐harmonically pumped mixers and an in‐phase 110 GHz 3 dB power divider. The IF output signals are in‐phase (I) branch and quadrature (Q) branch operating from DC±3.5GHz. In the back to back experimentaltests, it is shown that the conversion loss of the two 220 GHz I/Q mixers is less than 30 dB when the IF operating frequency is DC−3.5 GHz, IF input power is −10 dBm and the LO power is around 6 mW. Based on floating‐point simulation, the amplitude and phase imbalance of the I/Q mixer are less than 0.2 dB and 2 degree respectively. When the 220 GHz modulator and demodulator are set in a back to back configuration, a signal‐to‐noise ratio of 21 dB can be obtained using the 16QAM modulation type.