The power consumption of Radio Frequency (RF) electronics is a significant issue for Wireless systems. Since most wireless systems are portable and thus battery operated, reductions in DC power consumption can significantly reduce the weight and/or increase the battery lifetime of the system. As transmission consumes significantly more power than reception for most Wireless applications, previous efforts have been focused on increasing the efficiency of RF power amplification. These efforts have resulted in large increases in transmit efficiencies with research-grade amplifier efficiencies approaching 100%. In this paper, they describe their efforts on reducing power consumption of reception and other small signal RF functions. Additionally, recent power efficiency measurements on InP HEMT devices for transmission are presented. This work focuses on the needs of today's typical portable Wireless systems, which operate at frequencies up to several GHz.

Unlike other examples of fermion pair production in e{sup +}e{sup -} collisions, we show that top-quark pairs are produced in an essentially unique spin configuration in polarized e{sup +}e{sup -} colliders at all energies. Since the directions of the electroweak decay products of polarized top-quarks are strongly correlated to the top-quark spin axis, this unique spin configuration leads to a distinctive topology for top-quark pair events which can be used to constrain anomalous couplings to the top-quark. A significant interference effect between the longitudinal and transverse W-bosons in the decay of polarized top-quarks is also discussed.

The theory of the control of multiple shakers driving a single test item is reviewed. Several improvements that have been introduced since the original papers on the subject will be discussed. The improvements include: (1) specification of the control spectra; (2) the control of non-square systems (the number of shakers does not have to be equal to the number of control points); (3) the connection between sine testing, waveform control, and random control; (4) improvements in feedback control; (5) overlap-add versus time domain randomization; and (6) reproduction of non-Gaussian waveforms.