An antenna apparatus includes a dielectric base, and a plurality of feeding-radiating elements having different resonance frequencies, each including a feeding electrode and a radiating electrode which are disposed on surfaces of the base. A binary to ternary encoder has an input coupled to an output of the converter. The method also includes applying the electric field to the multiplication region, receiving a current output from the multiplication region, and varying the electric field in time, whereby a portion of the current output is suppressed. A metallic heat sink with a top wall and a side wall has an inner cavity, where the electronic driver circuit is located. The first and second tunnel quantum dots are of unequal size which helps decouple the quantum computer from the environment. The bias causes the sweep roller to attract stray excess toner present on the background of the drum after development, thereby preventing a toner image from being blurred.