A two-phase switching hybrid supply modulator for polar transmitters with 9% efficiency improvement

Abstract This paper deals with the symbolic solution of the switched current circuits. As is described, the full graph method of the solution can be used for finding relationships expressing current transfer, too. The summa MC-graph is constructed using two-graphs method in two-phase switching. By comparing the matrix form with results of the Mason’s formula are derived relations for current transfers in all phases. There are discussed various options described transistor memory cells - with loss and lossless transistors and normal transistor current mirror. Evaluation of the graph is simplified if we consider the lossless transistors or if the y21 -parameter of one transistor is alpha multiple of second ones.

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Effect of Shock Loading on the Microstructure of Uniloy 326

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100052535 ◽

1974 ◽

Vol 32 ◽

pp. 504-505

Author(s):

K. P. Staudhammer ◽

L. E. Murr

Keyword(s):

Grain Size ◽

Shock Loading ◽

Current Investigation ◽

Two Phase ◽

05 C ◽

Shock Deformation ◽

Heat Treated

The effect of shock loading on a variety of steels has been reviewed recently by Leslie. It is generally observed that significant changes in microstructure and microhardness are produced by explosive shock deformation. While the effect of shock loading on austenitic, ferritic, martensitic, and pearlitic structures has been investigated, there have been no systematic studies of the shock-loading of microduplex structures.In the current investigation, the shock-loading response of millrolled and heat-treated Uniloy 326 (thickness 60 mil) having a residual grain size of 1 to 2μ before shock loading was studied. Uniloy 326 is a two phase (microduplex) alloy consisting of 30% austenite (γ) in a ferrite (α) matrix; with the composition.3% Ti, 1% Mn, .6% Si,.05% C, 6% Ni, 26% Cr, balance Fe.

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Exsolution and inversion in pigeonite from the Whin Sill, Northern England

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100109513 ◽

1978 ◽

Vol 36 (1) ◽

pp. 474-475

Author(s):

P.P.K. Smith

Keyword(s):

High Temperature ◽

Low Temperature ◽

Homogeneous Nucleation ◽

Silicate Mineral ◽

Antiphase Boundaries ◽

Two Phase ◽

Primitive Form ◽

The Core ◽

Nucleation Mechanisms ◽

And Inversion

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.

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Shock consolidation of Ni-Ti alloy powder

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143730 ◽

1986 ◽

Vol 44 ◽

pp. 430-431

Author(s):

Naresh N. Thadhani ◽

Thad Vreeland ◽

Thomas J. Ahrens

Keyword(s):

Alloy Powder ◽

Amorphous Material ◽

Ti Alloy ◽

Two Phase ◽

Near Surface ◽

Optical Micrograph ◽

Shock Compaction ◽

Powder Particles ◽

Ti Powder ◽

Rapidly Solidified

A spherically-shaped, microcrystalline Ni-Ti alloy powder having fairly nonhomogeneous particle size distribution and chemical composition was consolidated with shock input energy of 316 kJ/kg. In the process of consolidation, shock energy is preferentially input at particle surfaces, resulting in melting of near-surface material and interparticle welding. The Ni-Ti powder particles were 2-60 μm in diameter (Fig. 1). About 30-40% of the powder particles were Ni-65wt% and balance were Ni-45wt%Ti (estimated by EMPA).Upon shock compaction, the two phase Ni-Ti powder particles were bonded together by the interparticle melt which rapidly solidified, usually to amorphous material. Fig. 2 is an optical micrograph (in plane of shock) of the consolidated Ni-Ti alloy powder, showing the particles with different etching contrast.

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