Novel design concept of waveguide mode adapter for low-loss mode conversion

2001 ◽  
Vol 13 (7) ◽  
pp. 675-677 ◽  
Author(s):  
Soon Ryong Park ◽  
Beom-Hoan O
Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 14
Author(s):  
Andres Osorio Salazar ◽  
Yusuke Sugahara ◽  
Daisuke Matsuura ◽  
Yukio Takeda

In this paper, the concept of scalability for actuators is introduced and explored, which is the capability to freely change the output characteristics on demand: displacement and force for a linear actuator, angular position and torque for a rotational actuator. This change can either be used to obtain power improvement (with a constant scale factor), or to improve the usability of a robotic system according to variable conditions (with a variable scale factor). Some advantages of a scalable design include the ability to adapt to changing environments, variable resolution of step size, ability to produce designs that are adequate for restricted spaces or that require strict energy efficiency, and intrinsically safe systems. Current approaches for scalability in actuators have shortcomings: the method to achieve scalability is complex, so obtaining a variable scaling factor is challenging, or they cannot scale both output characteristics simultaneously. Shape Memory Alloy (SMA) wire-based actuators can overcome these limitations, because its two output characteristics, displacement and force, are physically independent from each other. In this paper we present a novel design concept for linear scalable actuators that overcome SMA design and scalability limitations by using a variable number of SMA wires mechanically in parallel, immersed in a liquid that transmits heat from a separate heat source (wet activation). In this concept, more wires increase the maximum attainable force, and longer wires increase the maximum displacement. Prototypes with different number of SMA wires were constructed and tested in isometric experiments to determine force vs. temperature behavior and time response. The heat-transmitting liquid was either static or flowing using pumps. Scalability was achieved with a simple method in all tested prototypes with a linear correlation of maximum force to number of SMA wires. Flowing heat transmission achieved higher actuation bandwidth.


ASAIO Journal ◽  
2005 ◽  
Vol 51 (2) ◽  
pp. 33A
Author(s):  
Ramamoorthy Ramaswamy ◽  
Krishnamoorthy Ramaswamy ◽  
Ramaswamy Ganapathy

Frequenz ◽  
2018 ◽  
Vol 72 (7-8) ◽  
pp. 301-313 ◽  
Author(s):  
Mohammad Fazaelifar ◽  
Shahrokh Jam ◽  
Raheleh Basiri ◽  
H. Reza Azadi

Abstract In this paper at first, the ordinary septum polarizer has been designed and used for parabolic reflector feed in Ground station antenna. Next, a novel design of modified septum polarizer with wider beam-width is proposed for satellite antenna. Compactness, low weight, large bandwidth, high TX/RX isolation, low axial ratio as well as low loss are the advantages of the septum polarizer. The designed antenna has high purity circular polarization ( $\left| {AR} \right| \le 1.6dB$ ) and low return loss. The frequency bandwidth of the antenna is about 27 % in the center frequency 11 GHz and the TX/RX isolation is better than 32 dB. Finally the septum polarizer, modified septum polarizer and reflector are fabricated and tested and there were good agreement between simulation and measurement results.


2000 ◽  
Author(s):  
Wen-Ching Chang ◽  
Han-Bin Lin ◽  
Kuo C. Wei ◽  
Li-Ying Chang
Keyword(s):  
Low Loss ◽  

2017 ◽  
Vol 24 (1) ◽  
pp. 561-574 ◽  
Author(s):  
Li-Ya Ma ◽  
Anis Nurashikin Nordin ◽  
Norhayati Soin

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