Circuit Theory Analysis of Aperture Coupled Patch
Antenna for Wireless Communication
, Mohammad Aneesh
, Kumari Kamakshi
, and J. A. Ansari
NMAM Institute of Technology, Nitte, India
University of Allahabad, Allahabad, India
Institute of Management Studies, Ghaziabad, India
, e-mail: firstname.lastname@example.org
Received in final form July 9, 2017
Abstract—An analysis of dual band aperture coupled microstrip patch antenna is performed using modal
expansion cavity model. The theoretical investigation of antenna characteristics such as return loss,
VSWR and radiation pattern is represented. The influence of geometric parameters of the aperture
coupled microstrip patch antenna, such as aperture length and width, height of the substrate, dielectric
constant are also investigated. It is found that antenna resonates at two distinct modes i.e. 4.39 and 5.55
GHz for lower and upper resonance frequencies respectively. The bandwidth of the aperture coupled
microstrip patch antenna at lower resonance frequency is 10.23% (theoretical) and 13.33% (simulated)
whereas at upper resonance frequency, it is 5.69% (theoretical) and 3.59% (simulated). The frequency
ratio obtained for upper to lower resonance frequencies for theoretical and simulated results are 1.5 and
1.37 respectively. The theoretical results are compared with IE3D simulation results along with reported
experimental results and they are in close agreement.
Microstrip antenna has gain lot of attention by researchers. Due to its attractive features such as light
weight, low fabrication cost, linear as well as circular polarization, ultra wide, dual and triple frequency
operation [1, 2]. It has some limitations such as narrow bandwidth, low efficiency, low gain, extraneous
radiation from feeds and junctions. All these limitations can be removed by microstrip patch antenna (MPA)
using aperture feeding.
Aperture feeding technique is proposed firstly in . Thereafter, only few papers report for aperture
coupling [4–22]. This is because fabrication and analysis of these antennas are difficult.
In  the authors have suggested to analysis aperture coupling MPA using cavity model and there results
are compared with method of moment and measurement results. Later, the authors  propose antenna for
multifunctional applications having aperture coupling stacked patch, thereafter in  the authors suggested
the method of moment to analysis aperture coupling and validated with their measurement results.
Thereafter, the authors  have analyzed an aperture couple antenna using full wave analysis, whereas
extension of cavity method to analyze aperture coupled MPA with thick ground plane and a titled feeding
line [10–21] is reported. Further, the authors  developed design formulae for aperture coupled MPA. The
above reported techniques used to analyze aperture coupling are unable give clear view of the effect of
dielectric substrate, circuit diagram and current distribution on the antenna performance.
In this paper, emphasis is given on theoretical analysis of aperture coupled stacked patch antenna for dual
band operation. Theoretical analysis of aperture coupled stacked patch antenna has been presented using
circuit theory concept based on modal expansion cavity model. The effect of height of substrate, length and
width of aperture, dielectric substrate on antenna characteristics such as return loss, VSWR and radiation
pattern is discussed. Theoretical results obtained from the analysis are compared with IE3D simulation and
reported experimental results. The detail investigation of aperture coupled stacked patch antenna design,
theoretical considerations, discussion of results along with conclusion are discussed in next section.
ISSN 0735-2727, Radioelectronics and Communications Systems, 2018, Vol. 61, No. 4, pp. 168–179. © Allerton Press, Inc., 2018.
Original Russian Text © A. Singh, M. Aneesh, K. Kamakshi, J.A. Ansari, 2018, published in Izvestiya Vysshikh Uchebnykh Zavedenii, Radioelektronika, 2018, Vol. 61,
No. 4, pp. 226–238.