Linear array modules with prescribed excitations using waveguide shunt slot-fed microstrip patch elements

Abstract

A waveguide shunt slot-fed microstrip patch antenna (WGMPA) element is proposed and analyzed with method of moments (MOM) using entire-domain basis functions. The developed analysis has been utilized to obtain parametric observation of power-coupling versus transverse offset of feeding slot from the waveguide axis. Expressions for the radiation pattern as a summation of contributions of individual basis functions are reported. The proposed element is amenable to building-up series-fed linear arrays by a simple cascading of elements at the through-end of the feeding waveguide. The authors propose that arbitrary amplitude excitations may be applied to such linear arrays for desired tailored array pattern characteristics. The required transverse offsets for each array element may be computed using the reported parametric result. As a demonstration of concept, two distributions are designed – uniform amplitudes and Dolph–Chebyshev for reduced side lobes. Computed element patterns from MOM are used with an array factor formulation for arbitrary element positions. Both modules show radiation characteristics closely matching the expected directivity and sidelobe envelopes. Analysis validation is achieved using a proven finite element method (FEM)-based solver; the comparison is close and is reported. Efficacy of the waveguide shunt-slot fed patch element for building linear array modules with prescribed amplitude distributions is thus established.

Wide‐band circularly polarised antenna array using sequential phase feed structure and reinforced square radiating patch element

“…The sequential phase (SP) feed structure which is connected to the sequential rotated (SR) patch elements is one of the most important design approach which has been introduced in recent years. This technique has a better CP characteristic compared with series feed [17] and parallel feed [18] techniques. The main goal in array design is reducing the side lobe level in the array radiation pattern with less complexity.…”

A broad band circularly polarized cross slot cavity back array antenna with sequentially rotated feed network for improving gain in X-band application

“…Hitherto, many CP array antennas with various techniques to achieving circular polarization properties have been reported in [1–10]. Some famous techniques are presented for obtaining CP feature in microstrip antennas, for example: (I) series feed [11], (II) parallel feed [12], and (III) sequentially rotation feed [13]. Two first types of these methods are traditional and have many limitations such as: hard to realize and increased length of array in method I, unacceptable mutual coupling effect between elements and feed network and unbalanced pattern in method II.…”

“…Two first types of these methods are traditional and have many limitations such as: hard to realize and increased length of array in method I, unacceptable mutual coupling effect between elements and feed network and unbalanced pattern in method II. In recent years, many researches have been introduced the corporate-fed arrays consist of sequentially rotated method [1, 2, 11–13]. The results show that great improvement in AR operation has been achieved.…”

Circularly polarized slot antenna array with sequentially rotated feed network for broadband application

“…The use of circularly polarized (CP) antennas have advantages such as: very effective in combating multipath interferences or fading, able to reduce the “Faraday rotation” effect due to the ionosphere and no strict orientation between transmitting and receiving antennas are required . The inherent narrow axial‐ratio (AR) bandwidth of the conventional patch antenna leads to limit their applications.…”

“…Coplanar Waveguide (CPW) and microstrip line feeds are the most preferred feeding structures for the slot antenna design. Hitherto, several feed techniques are introduced for achieving CP property in microstrip arrays, for instance: (I) series feed , (II) parallel feed , and (III) sequentially rotation feed . Methods I and II are traditional and have some drawbacks in realization of this types of arrays, which can be noted: increment effective length of array and hard to realize in method I, unbalanced pattern and mutual coupling effect between elements and feed network in method II.…”