Control of phase center and polarization in circular microstrip antennas

Pour, Z. Allahgholi; Shafai, L.

doi:10.1109/aps.2006.1710822

Cited by 10 publications

(5 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To this end, the primary feed should asymmetrically illuminate the reflector aperture with its phase center located at the focal point of the reflector. With such a dual-mode stacked microstrip antenna, the phase shift of ±90 o results in scanned primary main beams in which the phase centre of the feed itself is located at its physical center [9]. This center is then placed at the focal point F shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Virtual array antenna with displaced phase centers for GMTI applications

Pour

Shafai

Mehrabani

2011

2011 IEEE RadarCon (RADAR)

Self Cite

View full text Add to dashboard Cite

A novel multi-phase center reflector antenna is introduced for the Ground Moving Target Indicator (GMTI) applications. A single antenna is used to virtually make it more than one antenna by controlling the excitation modes of the dual-mode primary feed. First, the multi-mode primary feed is analytically modeled to study the concept in general. Then, the results are presented for the dual-mode stacked circular microstrip patch antenna placed at the focal point of an offset reflector antenna.

show abstract

Section: Resultsmentioning

confidence: 99%

Virtual array antenna with displaced phase centers for GMTI applications

Pour

Shafai

Mehrabani

2011

2011 IEEE RadarCon (RADAR)

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this article, a novel approach is proposed for the first time to electronically change the array inter-element spacing by displacing the phase center locations of its antenna elements. It has already been established that the phase center location of a single, dual-mode circular microstrip patch antenna can be controlled by the amplitude and phase of mode content factors [24][25][26][27][28] . Such an intriguing and inspiring displaced phase center capability is utilized herein for the first time to realize adaptive element spacing in antenna arrays, whose physical elements are uniformly spaced.…”

Section: Principles Of Adaptive Element Spacing In Linear Array Antenmentioning

confidence: 99%

“…Thus, any phase center displacement in an antenna element leads to an apparent change in its position. In general, the phase center location of a circular microstrip antenna is coincident with its physical center when it operates at a single mode, whether the dominant or a higher order mode 24 . However, if two or more modes are concomitantly excited, the phase center of the antenna may be displaced from the physical center of the patch.…”

Section: Principles Of Adaptive Element Spacing In Linear Array Antenmentioning

confidence: 99%

“…To obtain an equal amount of displacement, but in the opposite direction, one may only change the polarity of the applied phase shift. For a given |A 21 |, the maximum phase center displacement is realized when the phase shift between the modes is 0° and 180°, which moves the phase center away from the center along the + x and − x axis, i.e., ϕ o = 0° and ϕ o = 180°, respectively 24 . For further clarification, the phase center location of the dual-mode antenna is plotted in Fig.…”

Section: Principles Of Adaptive Element Spacing In Linear Array Antenmentioning

confidence: 99%

See 1 more Smart Citation

Principles of adaptive element spacing in linear array antennas

Mitha

Pour

2021

Sci Rep

View full text Add to dashboard Cite

A novel approach to linear array antennas with adaptive inter-element spacing is presented for the first time. The main idea is based upon electronically displacing the phase center location of the antenna elements, which determine their relative coordinates in the array configuration. This is realized by employing dual-mode microstrip patch antennas as a constitutive element, whose phase center location can be displaced from its physical center by simultaneously exciting two modes. The direction and the amount of displacement is controlled by the amplitude and phase of the modes at the element level. This in turn facilitates reconfiguring the inter-element spacing at the array level. For instance, a uniformly-spaced array could be electronically transformed into a non-uniform one without any mechanical means. The proposed idea is demonstrated in two- and three-element linear antenna arrays. The technique has the potential to control the radiation characteristics such as sidelobe levels, position of the nulls, and the beamwidths in small arrays, which are useful for adaptively controlling the array performance in emerging wireless communication systems and radars.

show abstract

“…For a microstrip antenna element, a smart approach to control the phase center is to excite multiple modes (fundamental mode and higher order mode[s]). 12 If the antenna functions at a single mode, the phase center will coincide with its physical center. However, combination of two or more modes helps move the phase center away.…”

Section: Introductionmentioning

confidence: 99%

Optimization ofvirtually aperiodiclinear sparse arrays

Aslan

2021

Micro & Optical Tech Letters

View full text Add to dashboard Cite

Multi-port multi-mode antenna elements have the ability to move their phase centers and modify their radiation patterns electronically. Arrays composed of such elements are referred to as virtually aperiodic arrays in this paper. Herein, optimization of the mode excitation coefficients in virtually aperiodic sparse linear arrays is proposed, by introducing novel design constraints with the aim of synthesizing wide-angle scanning, reconfigurable patterns, with grating/side lobe reduction. A dual-mode patch antenna is used for demonstration purposes. An efficient convex optimization based algorithm is adopted to optimize the excitation weight at each element mode port, while considering the mutual coupling effects. Through full-wave simulations, the effectiveness of the optimization in suppressing the unwanted radiation and adapting to different fields-of-view is shown. A novel investigation on the impacts of defining different mode excitation ratios on the radiation pattern characteristics is conducted.

show abstract

Control of phase center and polarization in circular microstrip antennas

Cited by 10 publications

References 2 publications

Virtual array antenna with displaced phase centers for GMTI applications

Virtual array antenna with displaced phase centers for GMTI applications

Principles of adaptive element spacing in linear array antennas

Optimization ofvirtually aperiodiclinear sparse arrays

Contact Info

Product

Resources

About