50-Gb/s Direct Conversion QPSK Modulator and Demodulator MMICs for Terahertz Communications at 300 GHz

Citations Over TimeTop 10% of 2014 papers

Abstract

We demonstrate direct quadrature modulator and demodulator monolithic microwave integrated circuits for future terahertz communications at 300 GHz based on the quadrature phase-shift keying (QPSK) modulation format. For the modulating and demodulating signal, we employed half-Gilbert cell mixers, which provide balanced signaling and moderate performance in conversion efficiency with a simple circuit configuration. In order to maintain the balance performance of the modulator and demodulator, passive baluns and couplers are implemented with thin-film microstrip lines, which exhibit less insertion loss than inverted microstrip lines (IMSLs), while the active mixers are based on IMSLs for short interconnections. The half-Gilbert-cell mixers have a wide enough operation bandwidth for high-throughput communications of more than 10% at 300 GHz. According to the static constellation of the modulator, imbalance is expected to be less than approximately ±0.6 dB ∠4 ° . A nonchip back-to-back experiment was conducted at up to 60 Gb/s, and 50-Gb/s operation was verified with a low bit error rate on the order of 10 -8 or less. The results demonstrate that the QPSK modulation scheme can be applied to double the data rate at terahertz frequencies.

Related Papers

• → An Ultra-Wideband Balun Using Multi-Metal GaAs MMIC Technology(2010)19 cited
• → A novel low-power high-date-rate BPSK demodulator(2011)2 cited
• → A Novel Wideband MMIC Active Balun(1990)8 cited
• → Design and implementation of BPSK demodulator for onboard satellite telecommand receiver(2015)
• Research and Implementation of BPSK signal Demodulation based on Costas(2012)