Demonstration of a switchless Class E/Fodd dual-band power amplifier

A 250 W dual-band power amplifier belonging to the Class E/F switching amplifier family is presented. The amplifier operates in the 7 MHz and 10 MHz HAM bands, achieving 16 dB and 15 d B gain with power added efficiencies (PAE) of 92% and 87% in those bands, respectively. It utilizes dual-resonant passive input and output networks to achieve high-efficiency Class E/Fodd operation at both frequencies of operation, allowing the same passive networks to be used for both frequency bands without the use of band-select switches

A 2.4-GHz, 2.2-W, 2-V fully-integrated CMOS circular-geometry active-transformer power amplifier

A 2.4-GHz, 2.2-W, 2-V fully integrated circular geometry power amplifier with 50 Ω input and output matching is fabricated using 2.5V, 0.35 pm CMOS transistors. It can also produce 450mW using a 1V supply. Harmonic suppression is 64dB or better. An on-chip circular-geometry active-transformer is used to combine several push-pull low-voltage amplifiers efficiently to produce a larger output power while maintaining a 50 Ω match. This new on-chip power combining and impedance matching method uses virtual ac grounds and magnetic couplings extensively to eliminate the need for any off-chip component such as wirebonds. It also desensitizes the operation of the amplifier to the inductance of bonding wires and makes the design more reproducible. This new topology makes possible a fully-integrated 2.2W, 2.4GHz, low voltage CMOS power amplifier for the first time

Isolation and properties of the catalytically active [gamma] subunit of phosphorylase kinase

Phosphorylase kinase is a complex enzyme in both structure and regulation. It has a subunit stoichiometry of ((alpha)(beta)(gamma)(delta))(,4), and the (alpha), (beta), and (delta) subunits have known regulatory functions, whereas the (gamma) subunit has a catalytic site. The (gamma) subunit, separated from the holoenzyme by reversed-phase high-performance liquid chromatography (HPLC), had no activity in the usual assay mixture, but was reactivated in the presence of Ca(\u27+2) and calmodulin (which is identical to the (delta) subunit). The renaturation and reactivation process, which is totally dependent on Ca(\u27+2) and calmodulin, is optimized under specific conditions of temperature, time, pH, the presence of a stabilizing protein such as bovine serum albumin or, and the concentrations of HPLC solvents and the (gamma) subunit. The reactivated (gamma) subunit, still in the presence of calmodulin, shared several properties with a (gamma)(delta) complex previously isolated, including the strong, Ca(\u27+2)-independent nature of the (gamma)-calmodulin bond. The (gamma) subunit free of calmodulin was obtained by reactivation of the HPLC-isolated (gamma) subunit with calmodulin bound covalently to agarose. After reactivation, the (gamma) subunit was eluted from the calmodulin-agarose with a solution containing 1.0 M Tris (pH 7.0), 1% Triton X-100, 1 mM EGTA, and 5 mM dithiothreitol. The isolated (gamma) subunit is catalytically active, but, unlike the holoenzyme activity, the (gamma) subunit is totally independent of Ca(\u27+2), although it can be activated by Ca(\u27+2) plus calmodulin. Apparent Km values of the (gamma) subunit for the substrates ATP and phosphorylase b are equivalent to those found for the activated form of phosphorylase kinase, but Vm values are only about 10% of those of other forms of the enzyme. Unlike the (gamma)(delta) complex, the (gamma) subunit is pH dependent in the range of 6.8 to 9.0. Free Mg(\u27+2) stimulates (gamma) subunit activity, whereas free Mn(\u27+2) is inhibitory. ADP is a competitive inhibitor with a Ki of 60 (mu)M. Finally, the (gamma) subunit was shown to phosphorylate many phosphorylase kinase substrates, including troponin I, troponin T, (kappa)-casein, and myelin basic protein

The Class-E/F Family of ZVS Switching Amplifiers

A new family of switching amplifiers, each member having some of the features of both class E and inverse F, is introduced. These class-E/F amplifiers have class-E features such as incorporation of the transistor parasitic capacitance into the circuit, exact truly switching time-domain solutions, and allowance for zero-voltage-switching operation. Additionally, some number of harmonics may be tuned in the fashion of inverse class F in order to achieve more desirable voltage and current waveforms for improved performance. Operational waveforms for several implementations are presented, and efficiency estimates are compared to class-E

Distributed active transformer - a new power-combining andimpedance-transformation technique

In this paper, we compare the performance of the newly introduced distributed active transformer (DAT) structure to that of conventional on-chip impedance-transformations methods. Their fundamental power-efficiency limitations in the design of high-power fully integrated amplifiers in standard silicon process technologies are analyzed. The DAT is demonstrated to be an efficient impedance-transformation and power-combining method, which combines several low-voltage push-pull amplifiers in series by magnetic coupling. To demonstrate the validity of the new concept, a 2.4-GHz 1.9-W 2-V fully integrated power-amplifier achieving a power-added efficiency of 41% with 50-Ω input and output matching has been fabricated using 0.35-μm CMOS transistor

Fully integrated CMOS power amplifier design using the distributed active-transformer architecture

A novel on-chip impedance matching and power-combining method, the distributed active transformer is presented. It combines several low-voltage push-pull amplifiers efficiently with their outputs in series to produce a larger output power while maintaining a 50-Ω match. It also uses virtual ac grounds and magnetic couplings extensively to eliminate the need for any off-chip component, such as tuned bonding wires or external inductors. Furthermore, it desensitizes the operation of the amplifier to the inductance of bonding wires making the design more reproducible. To demonstrate the feasibility of this concept, a 2.4-GHz 2-W 2-V truly fully integrated power amplifier with 50-Ω input and output matching has been fabricated using 0.35-μm CMOS transistors. It achieves a power added efficiency (PAE) of 41 % at this power level. It can also produce 450 mW using a 1-V supply. Harmonic suppression is 64 dBc or better. This new topology makes possible a truly fully integrated watt-level gigahertz range low-voltage CMOS power amplifier for the first time

Cross-differential amplifier

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches

Cross-differential amplifier

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches

Cross-differential amplifier

A cross-differential amplifier is provided. The cross-differential amplifier includes an inductor connected to a direct current power source at a first terminal. A first and second switch, such as transistors, are connected to the inductor at a second terminal. A first and second amplifier are connected at their supply terminals to the first and second switch. The first and second switches are operated to commutate the inductor between the amplifiers so as to provide an amplified signal while limiting the ripple voltage on the inductor and thus limiting the maximum voltage imposed across the amplifiers and switches