This paper presents a -band push-pull power amplifier integrated with a modified uniplanar quasi-Yagi antenna. In this circuit, corrugation is added to the truncated ground plane of the antenna so that it can be used for both out-of-phase power combining and second harmonic tuning. By using the active integrated antenna concept, this novel circuit eliminates the usage of an ordinary 180 hybrid at the power-amplifier output stage, therefore eliminating the losses associated with the hybrid, resulting in a compact and high-efficiency power-amplifier design with intrinsic second harmonic suppression. At an operating frequency of 4.15 GHz, a maximum measured power-added efficiency (PAE) of 60.9% at an output power of 28.2 dBm has been achieved. The measured PAE is above 50% over a 260-MHz bandwidth. Additionally, the second harmonic radiation is found to be 30 dB below the fundamental in both -and -planes. When the circuit is subjected to a two-tone test, the measured third-order intercept point is 37 dBm, about 10 dB above the 1 dB point.Index Terms-Active integrated antenna, FET amplifier, harmonic tuning, power-added efficiency, push-pull power amplifier.

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In this paper, we present two novel design architectures that utilizing either a periodic structure or an active integrated antenna (AIA) for harmonic tuning in transmitter frontend designs. These techniques promise to significantly improve the power amplifier efficiency, reduce losses and weight, as well as maintaining good linearity requirements of advanced wireless communication systems. We will illustrate these two concepts through several design examples that have been developed recently, including a power amplifier integrated with novel PBG ground plane for harmonic tuning and four push-pull PA design examples, where the AIA concept is implemented to allow antenna to serve as a power combiner, a harmonic tuning load, in addition to its original functionality as a radiating element.

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During swallowing, airway protection depends upon adequate glottal closure and laryngeal elevation to prevent the entry of substances into the airway. Three-dimensional changes in the upper airway during laryngeal muscle stimulation in a canine model were quantified in animals implanted with Peterson type stimulating electrodes in the inferior and superior portions of the thyroarytenoid muscle, together with a reference electrode. Computer tomography scanning was performed on an IMATRON scanner with a 3 mm slice thickness advanced at overlapping 1 mm increments. Stimulation of the thyroarytenoid muscle produced adductions of the vocal fold towards the midline and changes in the supraglottic region as well as the glottis; the glottic wall was compressed medially above and below the glottis. These results suggest that chronic neuromuscular stimulation can effect glottic protection by reducing the glottal opening and may be beneficial for patients with central control disorders affecting airway protection during swallowing.