Low-Dispersive Leaky-Wave Antenna Integrated in Groove Gap Waveguide Technology

Abstract

In this paper, the use of a dispersive prism with a triangular shape is proposed to reduce the dispersive radiation nature of a leaky-wave antenna in groove gap waveguide technology. The operation of gap waveguide technology is based on the use of metallic pins that act as an artificial magnetic conductor, so the electromagnetic fields are confined and guided in the desired directions. To control a leaky-wave radiation of these confined fields is possible by tailoring the height of the pins, its periodicity and the waveguide width. This radiation, as in any conventional leaky-wave antenna, is dispersive, leading to beam squint as frequency is varied. Here, we mitigate this beam squint by using a prism made of dispersive pins and choosing appropriately their periodicity and height. With this prism, the leaky-wave radiation is focused into one single direction in a wide frequency-band.This concept is demonstrated with a prototype designed to radiate at ϕ=41 • with a central frequency of 12 GHz and high-gain of 16.5 dBi. A 22% frequency bandwidth for the 3-dB realized gain at ϕ=41 • is achieved, and the main radiating direction, with half-power beamwidth of 5 • , steers only ±0.5 • from 11.4 to 13.4 GHz.

Analysis of Periodic Structures Made of Pins Inside a Parallel Plate Waveguide

“…There are two main parameters we need to consider, namely the range of values achieved by the different structures (as all of them have the same basic element and periodicity) and how flat these lines are in frequency, as this will measure the dispersion of the element. The results can be used for designing wideband lenses [21], making use of the low dispersion characteristic, or conversely to design a structure that requires a very dispersive unit cell as in [15].…”

“…On the other hand, these pin structures have been also used to create effective refractive indices without using dielectrics. This property was used to design lenses [14] or even prisms to compensate the dispersion of a conventional leaky wave antenna [15]. For this type of application, the structure of the pins is well located within the parallel plate structure and modifies the dispersion characteristics of the first propagating mode.…”

3D-Printed Sievenpiper Metasurface Using Conductive Filaments

“…This can be achieved using bed of metallic pins [10], metallic spring-like structures [11], or a metallic "mushroom-like" structure proposed in [12], amongst others [13]. The use of metasurfaces to create stop-bans has led to several applications in electromagnetic high frequency topologies, such as electromagnetic packaging to suppress higher order modes in printed circuit boards (PCBs) and amplifiers cavities [11,[14][15][16][17], or gap-waveguides [10], which are structures that are widely study, and nowadays candidate for many high frequency applications [18][19][20]. One of the drawbacks of the use of these structures is with respect to its manufacture process.…”

Design of a 38 dBi Slot Array on Gap Waveguide at 140 GHz

“…A novel W-band low-profile monopulse slot array antenna on ridge gap waveguide has been reported in [10]. A novel leakywave antenna on groove gap waveguide has been recently presented in [11]. Some passive filters and novel transition structures based on gap waveguide technology have been reported in [12]- [15].…”