Design of monopulse radial line slot antennas

The authors propose the design of one radial line slot antenna with two simultaneous beams, one broadside beam and one conical beam. The antenna is a radial line slot antenna, with the slots placed on the upper plate in concentric rings. The radiation element is a slot pair, designed for getting left hand circular polarization. The antenna has been designed for working between 13.4 and 14 GHz. Both beams are obtained independently through very simple excitation circuits. The conical beam is obtained by feeding directly with a coaxial probe, just in the center of the antenna, while the broadside beam is obtained by feeding through a microstrip circuit and four post excited with a difference phase equal to 90/spl deg/. Comparing both radiation patterns, amplitude and phase, theta and phi angles can be obtained

Design of linearly polarized parallel plate slot antennas

The authors propose a design method for calculating the position and length of the slots in a linearly polarized parallel plate slot antenna for 12 GHz. The beam is tilted 5” in order to improve the reflection coefficient and to reduce the grating lobes level. The antenna is filled with a dielectric of low constant, to reduce the total cost of the antenna. The feeding system is a resonant slotted waveguide placed at the bottom of the parallel plate

Double-beam parallel-plate slot antenna

This paper presents the design and prototyping of a double-beam linear polarized parallel-plate slot antenna at 12-GHz band. Each beam is separated 27.7/spl deg/ and 27.3/spl deg/, respectively, from broadside direction. Two different radiation patterns are generated, exciting the parallel plate from opposite sides. The radiating elements are composed by three parallel slots, the central slot is close to the resonance, while the side ones are designed to minimize the reflection inside the parallel plate. The length of the slots in the same row is kept constant (periodic walls), and the distance between columns is equal to 0.7 times the wavelength. The designs of the feeding networks and the design of the array of slots generate both beams, pointing toward Hispasat and Astra satellites simultaneously, at the same frequency band. The feeding networks are two microstrip circuits that excite two linear arrays of 24 patches, placed at both sides of the antenna, and generate both quasi-TEM mode plane waves inside the parallel-plate waveguide, propagating from one side to the other

Broadside parallel plate slot antenna without dielectric

A linearly polarized flat antenna with broadside beam radiation is presented in this paper. A rectangular slot array in the upper side of a parallel plate waveguide form the main antenna structure. In previous works, the authors have presented one and dual tilted-beam antennas [1-2] for the reception of Hispasat or Astra satellite emissions in the 12 GHz band. The problem of the broadside beam antenna is to avoid the grating lobes. The main goal of the work presented here is getting a low cost broadside antenna that does not need a dielectric material inside the parallel plate to solve the grating lobes problem

Synthesis of circularly polarized multiprobe feed radial line slot array

In previous articles, we presented an easy way to analyze a slot array fed through a radial line and the design of an array of slots placed in an Archimedes spiral. The analysis was based on a circuit approach where the circuit parameters have been estimated using the first propagation mode in the radial line and the far field theory. The Archimedes spiral design, obtained with only one probe, has an efficiency problem due to the reflected field, that can be solved with this multiprobe design. The paper describes the antenna design method, giving the slot position and angle to obtain a radial line slot antenna having circular polarisation and broadside main beam

Design method, analysis and prototypes of radial line slot antennas

The authors propose a design procedure and an analysis method for radial line slot antennas. Several prototypes have been fabricated to validate these methods. The design procedure is very simple, and can be included in software. The analysis method is required to be very fast, in order to design this kind of antennas. It considers only one variable per slot and calculates the coupling between the elements of the antenna. It has been validated with measurements and method of moment simulations. The first prototypes are for TV-DBS reception at 12.1 GHz. They have a narrow broadside beam. The last prototype is a monopulse antenna. The monopulse capability can be obtained by comparing two simultaneous beams. Two simultaneous beams are obtained, a sum one and a difference one

Linear polarization parallel plate slot antenna

We show the design of a linearly polarised flat antenna. The main goal is getting a low cost antenna to use for the reception of Hispasat satellite emissions in the 12 GHz band. The gain needed for the antenna is around 30 dBi. A rectangular array of slots in the upper side of a parallel plate waveguide form the main antenna structure. The guide is excited by one planar feeding structure consisting of an array of rectangular microstrip patches. We also modify the feeding network the design procedure and the materials used to build of the radiation surface

Analysis and design software for radial slot antennas

Analysis And Design Software For Radial Slot Antenna