Contents I. Introduction
As the patch antenna has wide applications in wireless communication at microwave range, but suffers different disadvantages such as size, gain and poor bandwidth etc. in order to improve the above disadvantages various research have been carried out. Using lumped parameter is one of such techniques but have their own challenges, which is further enhanced by using quasi-lumped parameters, some of them are interdigital capacitance, pad capacitance and inductor. These interdigital capacitances are connected in series and parallel combination [1]. These parameters help in designing of metamaterial for various microwave applications along with flexibility of circuit miniaturization [2]. In present era different work has been carried out in field of circuit miniaturization using theory of split ring resonators or by using loaded transmission line. Dielectric loading is another alternative for achieving electrically compact antenna but at much lower frequency as compare to proposed frequency setup in this work [3]. These methods are somehow reducing the size of antenna but also reduced radiative efficiency even the size reduction obtained by these methods are very marginal with very less flexibility and degree of freedom so far is variation of design are concern. The value of dielectric constant also plays important role in bandwidth and gain improvement [4] the effective dielectric constant changes with electrical length as well, hence lumped and quasi-lumped parameters plays an important role in changing the electric length and effective dielectric constant of patch antenna, when comparing with lumped parameter quasi-lumped parameter have good tradeoff between compactness of antenna as function of frequency [5] along with larger bandwidth, gain and multiband capabilities. Frequency selective surface is a well-known technique for multiband application and also used for polarization conversion [6] using the latest concept of available literature our proposed examine five design based on quasi lumped slot on metallic patch, the bandwidth of proposed antenna is highest when smaller section of interdigital capacitance slot is introduced but having poor gain and exhibits only single band of operations. The gain of the proposed design improves with multiband application by introducing inductance slot, pad capacitance slot and by increasing the interdigital capacitance slot section.
