An RF coil includes two coil portions that are spaced apart to define a slab therebetween. Each coil portion is a microstrip transmission line formed as a loop wherein the microstrip includes a conductive strip disposed on one side of a dielectric material and a ground plane disposed on the other side of the dielectric material. When energized, a uniform RF field is produced in the slab. An array of such RF coils arranged back to back can be formed to allow for the selective excitation of a desired slab.