In this paper, a design method for an over octave hybrid continuous mode power amplifier (PA) based on modified real frequency technique (MRFT) is proposed. The extended continuous class-F/F-1 modes greatly expand the design space, which provides the possibility of over octave design, the optimal impedances at internal current-generator (I-Gen) plane and package plane are investigated. Then a novel broadband matching network based on MRFT is presented for impedance match. To verify the proposed methodology, an over octave PA with radial stub is fabricated and measured. The PA achieves a bandwidth of 133% from 0.8GHz to 4GHz, over this frequency range, the drain efficiency is 58.3-68.7% and large-signal gain is greater than 9.6dB.

This paper describes the design method of a broadband CMOS stacked power amplifier using harmonic control over wide bandwidths in a 0.11,$mu $m standard CMOS process. The high-efficiency can be obtained over wide bandwidths by designing a load impedance circuit as purely reactive as possible to the harmonics with broadband fundamental matching, which is based on continuous Class-F mode of operation. Furthermore, the stacked topology overcomes the low breakdown voltage limit of CMOS transistor and increases output impedance. With a 5-V supply and a fixed matching circuitry, the suggested power amplifier (PA) achieves a saturated output power of over 26.7,dBm and a drain efficiency of over 38% from 1.6,GHz to 2.2,GHz. In W-CDMA modulation signal measurements, the PA generates linear power and power added efficiency of over 23.5,dBm and 33% (@ACLR $=-33$,dBc).

The first realization of a class-F InGaP/GaAs HBT amplifier considering up to 7th-order higher harmonic frequencies, operating at 1.9-GHz band, is described. A total number of open-circuited stubs for higher harmonic frequency treatment is successfully reduced without changing a class-F load circuit condition, using a low-cost and low-loss resin (tan δ=0.0023) circuit board. In class-F amplifier design at microwave frequency ranges, not only increasing treated orders of higher harmonic frequencies for a class-F load circuit, but also decreasing parasitic capacitances of a transistor is important. Influence of a base-collector capacitance, Cbc, for power added efficiency, PAE, and collector efficiency, ηc, was investigated by using a two-dimensional device simulator and a harmonic balance simulator. Measured maximum PAE and ηc reached 74.2% and 76.6%, respectively, using a fabricated class-F InGaP/GaAs HBT amplifier with collector doping density of 21016 cm-3. In case circuit losses were de-embedded for the experimental results, PAE and ηc were estimated as 78.7% and 81.2%, respectively. These are very close to obtainable maximum PAE for the use of the InGaP/GaAs HBT.

This paper presents a 0.5Vdd-step pumping method for Dickson-type charge-pump circuits that achieve high overall efficiency, including regulator circuitry, even at large output currents, and these circuits are targeted at mobile equipment applications. We have designed positive and negative charge-pump circuits which use a 0.5Vdd-step pumping method, are implemented with advanced control functions, and are fabricated with our custom CMOS process. Measured results showed that efficiency of a 2.5-stage positive charge-pump circuit before regulation is more than 93% (power supply Vdd=5 V, output voltage Vout=16.9 V 3.5Vdd, output current Iout=4 mA), and that of a 1.5-stage negative charge-pump circuit is 93% (power supply Vdd=5 V, output voltage Vout=-7.2 V -1.5Vdd, output current Iout=4 mA).

This paper presents improved versions of three-stage positive-output and two-stage negative-output Dickson charge-pump circuits which are intended to replace switching regulators in video-product CCD driver applications (where 12 V and -6.5 V are needed), and are designed and fabricated in a custom CMOS process. From a power supply Vdd of 4.0 to 5.5 V, the positive charge pump generates a positive output voltage of greater than 3.9Vdd, while the negative charge pump generates a negative voltage of greater than -1.9Vdd, both with efficiencies of greater than 94% at 2 mA output currents.

A 10-kW (53V/200A), forced-air-cooled DC-DC converter has been developed for fuel cell systems. This converter uses new high-voltage bipolar-mode static induction transistors (BSIT), a new driving method, a zero-voltage-switched pulse-width-modulation technique, and a new litz wire with low AC resistance. It weighs only 16.5kg, has a volume of 26,000cm3, operates at 40kHz, and has a power conversion efficiency of about 95%. The power loss of this converter is 20% less than that of conventional natural-air-cooled DC-DC converters, and the power density is 3 times as high.