Moment method analysis of a T-shaped slot radiator in bifurcated waveguide

Numerical analysis of irregular slots in slotted waveguide antennas

“…As outlined in Reference [4], slots fed by a dual-mode bifurcated waveguide can be used to achieve polarization agility. For example, circular polarization is provided by the combination of an axially polarized T-shaped slot and a transversely polarized longitudinal slot separated by a quarter of a waveguide wavelength, and excited by either the even mode or odd mode of the bifurcated waveguide.…”

“…It is also interesting to note that although the resonant frequency of the T-slot is very sensitive to its height, its reflection or radiation strength is relatively unaffected by its height in these selected examples. It is also pertinent to note that the radiation intensity of the side-wall T-slot is much stronger than that of the T-slot on the and [4]. It is well known that the inclined narrow-wall slot overlapping the broad wall of a waveguide, as illustrated in Figure 3, is commonly used in slotted waveguide antennas when axially directed polarization of the radiated signal is desired.…”

Efficient moment method analysis of a rectilinear edge-slot radiator in rectangular waveguide

“…The other matrix elements [B], [C], and [D], are calculated in a similar fashion as indicated in Sangster and Lyon (1982) . The Green's functions --G yy a for rectangular waveguide (region a), for a slot cavity (region b) and for the half space (region c) are taken from Wang (1994).…”

“…The approach taken involves resolving the inclined edge slot into three basic components; a parasitically excited transversely directed element in the side-wall, active longitudinally directed elements in the side-wall, and transversely directed elements in the broad wall. Suitable basis functions for the resolved slot can be determined by employing the resonated transmission line approach described in Sangster and Lyon (1982), and Sangster and McColl (1996), and once appropriate waveguide Green' s function components are identi® ed the moment method equations can readily be established as indicated in } 2. Note that for the`resolved slot' the transverse element is considered to be`parasitic' for axially polarized radiations and does not provide direct coupling between the waveguide and radiated ® elds.…”

A polarisation agile T-shaped slot antenna fed from balanced microstripline

“…Any antenna element which is capable of radiating two independent, orthogonally polarised field components can achieve polarisation control. This has been accomplished in the recent past by the use of suitably shaped slots in bifurcated waveguide, for example the Xslot, Ajioka et al (1), and the T-slot, Sangster and Lyon (2). Field polarisation is varied by electronically adjusting the relative phase between the signals entering the input ports of the bifurcated waveguide.…”