for any cases, if we want to make an antenna then it is better to go for DRA rather than patch,dipole etc type antenna..................it has very low surface wave while compared to other......no conduction loss...........degree of freedom to choose the dimension of the antenna is very very high ie flexible in the case for DRA..........it is better to say specifically rectangular DRA............IEEE paper is there which compared MICROSTRIP PATCH antenna & DRA..........i forgot-please check ur self............these r the ADVANTAGES.....................
disadvantages ---------resonant frequency is inversely proportional to the square root of there relative permittivity of DRA......hence low permittivity such as 10 can give very high resonant frequency theoretically-------------but at that time surface wave losses are also high while compared to medium of high value of permittivity.............hence more shifting of resonant frequency between theoretical and experimental results.....................high resonant frequency means very low size of the DRA.............for that case to excite that very small DRA we have to go for CPW feed rather than probe feed............
one laughing disadvantage is its dimension...........patch has 2D dimension.........planner structure---------------but DRA has 3d dimension-----------more space is needed to place it.he he..........its a joke--------
more frankly DRA has a lot of advantages while compared to disadvantages.............