scholarly journals Tunable millimetre‐wave phase shifting surfaces using piezoelectric actuators

2014 ◽  
Vol 8 (11) ◽  
pp. 829-834 ◽  
Author(s):  
Marina Mavridou ◽  
Alex P. Feresidis ◽  
Peter Gardner ◽  
Peter S. Hall
Author(s):  
Claude Gibert ◽  
Vsevolod Kharyton ◽  
Fabrice Thouverez ◽  
Pierrick Jean

An experimental setup is described which permits to rotate a bladed disk in vacuum and to measure its dynamic response to excitations provided by some embedded piezoelectric actuators. A particular spatial placement of actuators associated with phase-shifting electronic circuits is set for simulating travelling wave excitations with respect to the rotating frame. The system is demonstrated on an actual high-pressure compressor (HCP) integrally bladed disk. The dynamic response of the blisk is analyzed experimentally and results are correlated with those obtained from a simplified finite elements model taking into account Coriolis effect. The paper focuses on the influence of the latter which is most of the time neglected and its implication on the forced response levels is studied into two situations without or with mistuning.


Author(s):  
Min Zhang ◽  
Xiaofeng Sun ◽  
Hong Shen ◽  
Yuchao Yuan ◽  
Baocheng Wang ◽  
...  

2020 ◽  
Vol 10 (17) ◽  
pp. 5800 ◽  
Author(s):  
Devika Dass ◽  
Sean O'Duill ◽  
Amol Delmade ◽  
Colm Browning

The future evolution of wireless networks, throughout the 5G era and beyond, will require the expansion and augmentation of millimetre-wave systems for both terrestrial and satellite communications. Photonic technologies offer a cost efficient and high bandwidth platform for millimetre-wave carrier generation and distribution, but can introduce high levels of phase noise through optical heterodyning, which is highly problematic for mobile signal waveforms. In this work, a detailed analytical model of a hybrid photonic/mm-wave system is developed and discussed. Through careful system design, the system is found to support both 5G compatible multi-carrier (OFDM) and single carrier (APSK) modulation at 60 GHz. APSK is found to offer higher tolerance mm-wave phase noise compared to OFDM, ultimately easing optical linewidth restrictions to ∼30 kHz. The model is extended to include a novel millimetre wave phase noise cancelling receiver, which is shown to significantly alleviate these restrictions even further—enabling phase noise free mm-wave operation for optical linewidths up to ∼2 MHz. Detailed analysis and discussion of this extended system lead to the establishment of a theoretical relationship between the mm-wave receiver design and the achievable system performance in terms of error vector magnitude (EVM). Excellent matching of the predicted theoretical with simulated performances is shown.


1979 ◽  
Vol 15 (2) ◽  
pp. 48 ◽  
Author(s):  
Elias Kpodzo ◽  
Günther Begemann ◽  
Klaus Schünemann

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