The present invention relates to techniques to excite a circularly polarized antenna and, more particularly, to a circularly polarized antenna having a QUAD-EMC unit structure. The compartment includes a reservoir structure, in turn, defining a plurality of ink reservoirs from which respective ink outlets extend. The grommet defines a vent path for the accumulator and includes a hollow generally cylindrical shaft. In an embodiment of the present invention, a novel system for mobile data processing is provided. If the infection extends to the eardrums, making the Valsalva maneuver painful, or if the patient is simply unusually sensitive, then earplugs to reduce the stress on the eardrums may be worn while the patient performs the Valsalva maneuver. The rear at the middle of the insert hole has a trigger, such that if a pencil is inserted, the trigger sends a signal to the driving source to start sharpening the pencil.