Two wideband left-handed (LH) transmission lines are presented. A pure LH transmission line (PLH TL) materialized by a defected ground structure with an inter-digital capacitor on a microstrip line has a wide LH propagation region without a right-handed (RH) branch in the reduced Brillouin zone. Another is a broadband LH rectangular waveguide utilized by a shorted stub and twisted Eplane posts....

In this paper, a broadband rectangular microstrip patch antenna fed by coplanar waveguide feed with two slots in the ground plane is proposed. Investigations are carried out using coplanar waveguide feed with slotting in the ground plane to optimize the broadband operation. A sensitivity analysis shows the variation of return loss with different antenna parameters. This design of broadband ante...

New formulas are presented for the reflection coefficient at the open end of a rectangular waveguide radiating into air including the effect of wall thickness or flange. Existing formulas require significant amount of numerical calculations and do not cover the practical range of waveguide dimensions. Reflection coefficients of open-ended standard waveguides are simulated using commercial elect...

A small 4-cavity assembly designed to operate at W-band was built using OFE copper parts machined by wire and plunge EDM proocesses. The machined pieces were then diffusion bonded together. A cutaway section of one the cavity modules is shown in figure 1. Each of the four cavities approximates a one-half guided wavelength at 90 Ghz of reduced height WR 10 waveguide coupled to full height WR10 w...

A theoretical formulism based on the boundary matching technique has been proposed to study the systematic of an asymmetric waveguide coupler. Same formulism is applicable to a symmetric coupler. The equivalent parallel coupling length to account for the coupling in the two S-shaped regions in the input and the output of the coupler is obtained from the coupler geometry and is dealt with more a...

Recently, has emerged a n ew technology, substrate integrated waveguide (SIW) [1] [2], it has been applied successfully to the conception of planar compact components for the microwave and millimeter waves applications [3] [4]. Our study concerns the analysis of right bends of rectangular waveguides under SIW technology by the HFSS code, in order to simulate different chamfrain positions, throu...

We report the observation of de-chirping of a linearly chirped (in energy) electron bunch by its passage through a 4 inch long rectangular waveguide loaded with two silicon bars 0.25 inch thick and 0.5 inch wide. Silicon being a semiconductor has a conductivity that allows it to drain the charge fast in case if some electrons get intercepted by the dechirper. At the same time the conductivity i...

The majority of up-to-date conceived composite right-handed / left-handed (CRHLH) transmission lines (TL) are open configurations derived from microstrip technology. We present here a closed CRHLH architecture derived from the H10 rectangular hollow waveguide mode, which is realised in substrate-integrated waveguide (SIW) technology and is thus easy to fabricate. The dispersion characteristic i...

A low-cost, high-performance -band Gunn diode oscillator for educational and research purposes has been developed. The cavities have been manufactured on a standard WR90 rectangular waveguide with UBR100 flange in order to make it compatible with the waveguide circuitry usually available in a basic microwave laboratory. The capability of sweeping the whole band at constant output power and low ...

We present a modeling technique for the interaction of an elliptical-shape crack in a metal with an open-ended waveguide. The crack is first modeled by an appropriate number of short rectangular waveguides. The mode-matching technique is then used to calculate the scattering matrix of the new segmented waveguide structure. The probe reflection coefficient of the dominant mode is finally calcula...