A fully-integrated 1.8-V, 2.8-W, 1.9-GHz, CMOS power amplifier

This paper demonstrated the first 2-stage, 2.8W, 1.8V, 1.9GHz fully-integrated DAT power amplifier with 50Ω input and output matching using 0.18μm CMOS transistors. It has a small-signal gain of 27dB. The amplifier provides 2.8W of power into a 50Ω load with a PAE of 50%

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

Planar sandwich antennas for submillimeter applications

A planar receiving antenna with a predictable pattern at submillimeter wavelength is demonstrated experimentally for the first time. It is single lobed and efficient, with a gain of approximately 8 dB at a wavelength of 119 µm

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

A study of factors effecting the herbicidal control of yellow nutgrass (Cyperus esculentus L.)

The objective of this research was to determine if tuber scarification and potassium gibberellate treatment improved the effective-ness of four herbicides in killing yellow nutgrass (Cyperus esculentus L.). Scarification was studied as a method for improving herbicidal penetra-tion into the nutgrass tuber. Potassium gibberellate was evaluated for its effectiveness in promoting starch hydrolysis in the mother tuber. It was applied as a soak to the germinating tubers alone and in combina-tion with soil applications of s-ethyl dipropylthiocarbamate (EPTC) or 2\u27chloro-2,6-diethyl-n-methoxymethyl acetanilide (alachlor). Potassium gibberellate was also applied alone as a foliar spray and in combination with a foliar application of 3-amino-s-triazole (amitrole) or 3-(3,4- dichlorophenyl)-1-methoxy-1-methylurea (linuron). Plant height, fresh and dry weight, total air dry root weight, and free glucose and starch content of the mother tubers were determined at one, five, and nine weeks after herbicide treatment. Tuber scarification did not improve herbicidal effectiveness in killing yellow nutgrass. The tuber soak of potassium gibberellate did not influence plant growth or form of tuber carbohydrate content. Foliar applications of potassium gibberellate increased plant height, but the increase was not associated with a change in type of carbohydrate of the mother tuber, and did not improve the herbicidal effectiveness in killing nutgrass. EPTC greatly inhibited nutgrass plant and root growth. There was a delay in the availability of free glucose in EPTC treated tubers. Starch utilization in the mother tubers was greatly inhibited, but hydrolysis occurred over the nine-week period. Alachlor inhibited nutgrass foliage and root growth for four weeks after treatment. Starch utilization was inhibited by alachlor, but hydrolysis occurred over the nine-week period. Foliar applications of amitrole and linuron were effective in reducing nutgrass plant growth. Free glucose decreased in tubers treated with these chemicals. There was no significant difference in the initial and final starch content of the amitrole. or linuron treated tubers. However, starch content in amitrole and linuron treated tubers was significantly lower than that of the non-treated control at the termination of the experiment. Neither the amitrole nor the linuron treated tubers appeared viable at the termination of the experiment