ELLIPTICAL MICROSTRIP ANTENNA Resonant Resonant Resonant

above equation the first order formula for the resonant frequency of elliptical microstrip antenna on ferrite sub-strate is found to be (7) The effective permeability of the substrate is expressed as9 = (+ J , where C and D are a function of b/h. Similarly the effective permittivity is expressed as +*(I + 12h/b)-'j2 e, + I &e// = 2 2 which is also a function of b/h. Since b is not uniform throughout , the resonant frequency expressed by eqn. 7 is a very crude approximation. So an integrating averaging procedure is used to find the exact value of E,// and p e f J as where 2. 26 a b(x) =-[a2-(x-a)2]1'2 peffi is obtained by replacing b of pelf by (1/2a) JF b(x) dx. Using the above modifications the formula for the resonant frequency of the elliptical microstrip antenna on a ferrite sub-strate is found to be Results and conclusion: The resonant frequencies obtained using eqns. 7 and 8 are compared with the experimental result. Table 1 shows the comparison of the resonant frequencies. It can be seen from the analysis that the formula for the resonant frequency of the ferrite based microstrip antenna using E~~~~ and is more conceptually reasonable and provides a better accuracy for the resonant frequency of the microstrip antenna on a ferrite substrate. The resonant frequency is also 2001