Realtime Coherent cw THz System: Phase Modulation without Phase Modulator

2019 ◽  
Author(s):  
Lars Liebermeister ◽  
Simon Nellen ◽  
Robert B. Kohlhaas ◽  
Steffen Breuer ◽  
Martin Schell ◽  
...  
Keyword(s):  
Phase Modulation ◽  
Phase Modulator ◽  
System Phase

scholarly journals A review of terahertz phase modulation from free space to guided wave integrated devices

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hongxin Zeng ◽  
Sen Gong ◽  
Lan Wang ◽  
Tianchi Zhou ◽  
Yaxin Zhang ◽  
...  
Keyword(s):  
Free Space ◽  
Phase Modulation ◽  
Phase Change Materials ◽  
Guided Wave ◽  
Research Progress ◽  
Future Application ◽  
Phase Modulator ◽  
Phase Modulators ◽  
Tunable Materials ◽  
Core Technology

Abstract In the past ten years, terahertz technology has developed rapidly in wireless communications, spectroscopy, and imaging. Various functional devices have been developed, such as filters, absorbers, polarizers, mixers, and modulators. Among these, the terahertz phase modulation is a current research hotspot. It is the core technology to realize flexible control of the terahertz wavefront, beam scanning, focusing deflection. It is indispensable in terahertz wireless communication, high-resolution imaging, and radar systems. This review summarizes the research progress of terahertz phase modulators from the two major types: free space and guided wave integration. Among these, the free space terahertz phase modulator is realized by combining the tunable materials and artificial metasurfaces. Based on different types of tunable materials, the terahertz free space phase modulator combining the semiconductor, liquid crystal, phase change materials, graphene, and other two-dimensional materials are introduced, and the influence of different materials on the phase modulation performance is discussed and analyzed. The monolithic integration and waveguide embedding methods are introduced separately, and the characteristics of different forms of terahertz-guided wave phase modulation are also discussed. Finally, the development trends of terahertz phase modulators, possible new methods, and future application requirements are discussed.

scholarly journals 10 GHz pulse source for 640 Gbit/s OTDM based on phase modulator and self-phase modulation

2011 ◽  
Vol 19 (26) ◽  
pp. B343 ◽  
Author(s):  
Hao Hu ◽  
Hans Christian Hansen Mulvad ◽  
Christophe Peucheret ◽  
Michael Galili ◽  
Anders Clausen ◽  
...  
Keyword(s):  
Phase Modulation ◽  
Phase Modulator ◽  
Pulse Source ◽  
Self Phase Modulation

scholarly journals A Low-Noise Delta-Sigma Phase Modulator for Polar Transmitters

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Bo Zhou
Keyword(s):  
Power Dissipation ◽  
Phase Modulation ◽  
Finite Impulse Response ◽  
Low Noise ◽  
Phase Modulator ◽  
Digital Compensation ◽  
Phase Errors ◽  
Polar Transmitters ◽  
Delta Sigma ◽  
Peak Phase

A low-noise phase modulator, using finite-impulse-response (FIR) filtering embedded delta-sigma (ΔΣ) fractional-N phase-locked loop (PLL), is fabricated in 0.18 μm CMOS for GSM/EDGE polar transmitters. A simplified digital compensation filter with inverse-FIR and -PLL features is proposed to trade off the transmitter noise and linearity. Experimental results show that the presented architecture performs RF phase modulation well with 20 mW power dissipation from 1.6 V supply and achieves the root-mean-square (rms) and peak phase errors of 4° and 8.5°, respectively. The measured and simulated phase noises of −104 dBc/Hz and −120 dBc/Hz at 400-kHz offset from 1.8-GHz carrier frequency are observed, respectively.

scholarly journals Open-Loop Wide-Bandwidth Phase Modulation Techniques

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Nitin Nidhi ◽  
Pin-En Su ◽  
Sudhakar Pamarti
Keyword(s):  
Phase Modulation ◽  
Open Loop ◽  
Quantization Noise ◽  
Phase Modulator ◽  
Wide Bandwidth ◽  
Band Frequency ◽  
Power Efficient ◽  
Noise Transfer Function ◽  
Digital Phase ◽  
The Impact

The ever-increasing growth in the bandwidth of wireless communication channels requires the transmitter to be wide-bandwidth and power-efficient. Polar and outphasing transmitter topologies are two promising candidates for such applications, in future. Both these architectures require a wide-bandwidth phase modulator. Open-loop phase modulation presents a viable solution for achieving wide-bandwidth operation. An overview of prior art and recent approaches for phase modulation is presented in this paper. Phase quantization noise cancellation was recently introduced to lower the out-of-band noise in a digital phase modulator. A detailed analysis on the impact of timing and quantization of the cancellation signal is presented. Noise generated by the transmitter in the receive band frequency poses another challenge for wide-bandwidth transmitter design. Addition of a noise transfer function notch, in a digital phase modulator, to reduce the noise in the receive band during phase modulation is described in this paper.

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