Wave propagation in a double-sided exponentially tapered rectangular waveguide

1990 ◽  
Vol 38 (9) ◽  
pp. 1362-1365
Author(s):  
S.O. Ajose ◽  
C.N. Ndujiuba
Keyword(s):  
Wave Propagation ◽  
Rectangular Waveguide

scholarly journals Energy tunneling through narrow waveguide channel and design of small antennas

2011 ◽  
Vol 8 (1) ◽  
pp. 63-71
Author(s):  
Miranda Mitrovic ◽  
Branka Jokanovic
Keyword(s):  
Wave Propagation ◽  
Dielectric Permittivity ◽  
Transmission Coefficient ◽  
Rectangular Waveguide ◽  
Narrow Channel ◽  
Waveguide Channel ◽  
Small Antennas ◽  
Field Density ◽  
Effective Dielectric Permittivity ◽  
Small Antenna

In this paper we investigate the conditions for energy tunneling through narrow channel obtained by reducing the height of rectangular waveguide. Tunneling of the energy occurs at the frequency for which the effective dielectric permittivity of the channel becomes equal to zero, so it can be treated as an ENZ (epsilon-near-zero) metamaterial. We investigated how geometry of the channel and dielectric permittivity affect the transmission coefficient and field density in the channel. Adding slots in the channel, which are placed orthogonally to the wave propagation, we designed a small antenna with directivity of 5.44 dBi at the frequency of 3 GHz.

MEMS reconfigurable millimeter-wave surface for V-band rectangular-waveguide switch

2013 ◽  
Vol 5 (3) ◽  
pp. 341-349 ◽  
Author(s):  
Zargham Baghchehsaraei ◽  
Umer Shah ◽  
Jan Åberg ◽  
Göran Stemme ◽  
Joachim Oberhammer
Keyword(s):  
Wave Propagation ◽  
Insertion Loss ◽  
Rectangular Waveguide ◽  
Microelectromechanical Systems ◽  
Conductive Polymer ◽  
Comb Drive ◽  
V Band ◽  
Contact Points ◽  
Field Lines ◽  
Novel Concept

This paper presents for the first time a novel concept of a microelectromechanical systems (MEMS) waveguide switch based on a reconfigurable surface, whose working principle is to block the wave propagation by short-circuiting the electrical field lines of the TE10 mode of a WR-12 rectangular waveguide. The reconfigurable surface is only 30 µm thick and consists of up to 1260 micromachined cantilevers and 660 contact points in the waveguide cross-section, which are moved simultaneously by integrated MEMS comb-drive actuators. Measurements of fabricated prototypes show that the devices are blocking wave propagation in the OFF-state with over 30 dB isolation for all designs, and allow for transmission of less than 0.65 dB insertion loss for the best design in the ON-state for 60–70 GHz. Furthermore, the paper investigates the integration of such microchips into WR-12 waveguides, which is facilitated by tailor-made waveguide flanges and compliant, conductive-polymer interposer sheets. It is demonstrated by reference measurements where the measured insertion loss of the switches is mainly attributed to the chip-to-waveguide assembly. For the first prototypes of this novel MEMS microwave device concept, the comb-drive actuators did not function properly due to poor fabrication yield. Therefore, for measuring the OFF-state, the devices were fixated mechanically.

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