Exploring figures of merit associated with the suboptimum operation of class-E power amplifiers

Closed-form design equations for the operation of a class-E amplifier for zero switch voltage slope and arbitrary duty cycle are derived. This approach allows an additional degree of freedom in the design of class-E amplifiers which are normally designed for 50 duty ratio. The analysis developed permits the selection of non-unique solutions where amplifier efficiency is theoretically 100 but power output capability is less than that the 50 duty ratio case would permit. To facilitate comparison between 50 (optimal) and non-50 (suboptimal) duty ratio cases, each important amplifier parameter is normalised to its corresponding optimum operation value. It is shown that by choosing a non-50 suboptimal solution, the operating frequency of a class-E amplifier can be extended. In addition, it is shown that by operating the amplifier in the suboptimal regime, other amplifier parameters, for example, transistor output capacitance or peak switch voltage, can be included along with the standard specification criteria of output power, DC supply voltage and operating frequency as additional input design specifications. Suboptimum class-E operation may have potential advantages for monolithic microwave integrated circuit realisation as lower inductance values (lower series resistance, higher self-resonance frequency, less area) may be required when compared with the results obtained for optimal class-E amplifier synthesis. The theoretical analysis conducted here was verified by harmonic balance simulation, with excellent agreement between both methods. © The Institution of Engineering and Technology 2007.

Fragmentos de Soto de Rojas: a ‘new’ mythological fable of the Spanish Baroque

The twentieth-century poet Gerardo Diego’s commitment to the recovery of a ‘sub-genre’, the mythological fable, evident in his Fábula de Equis y Zeda (1930) has been acknowledged by Peinado Elliot (2006), among others. However a recent discovery in his archive has revealed a hitherto unknown aspect of the poet’s scholarly commitment to this endeavour. A transcription of a previously unpublished, and until recently, unknown Baroque mythological fable with the title ‘Fábula de Alfeo y Aretusa’ was recently found by his daughter Elena, alongside an unpublished study by the young poet of said fable entitled ‘Un poema manuscrito del siglo XVII de la biblioteca Menéndez Pelayo’. Rosa Navarro Durán (2012) is convinced that the correspondences with Soto de Rojas’ 'Los fragmentos de Adonis' and the clear imprint of Góngora’s 'Soledades' and his 'Fábula de Píramo y Tisbe' permit us to attribute it, with some confidence, to Pedro Soto de Rojas. This essay will consider the significance of this exciting discovery for our reading of Soto de Rojas’ existing corpus, exploring in particular the poem’s links with the dark eroticism of the Fragmentos de Adonis, (1652) and the early Fábula de la Naya.(1623)

A carefully curated collection: female figures as sites of inscription in Gautier’s Émaux et Camées

This article examines the ways in which female figures function as additional sites for poetic inscription in Gautier's Émaux et Camées. Although considerable attention has already been paid to the numerous and varied objects catalogued in the collection and, indeed, to the notion of the poems themselves as objects, the present study aims to expand upon such interpretations of the work by focusing on three texts, "Le Poëme de la femme", "Étude de mains : Impéria" and "La fellah". In these poems, female figures who, while they may at first be granted some agency (and be represented going about the business of daily, if highly stylized, life), are finally immobilized within the verse as their bodies, and particularly their pristine skin, ultimately function as an additional paper-like surface for the poet, permitting their assimilation into Gautier's diminutive private collection.

The Pindaric poetry of Cruz e Silva and the Neoclassical revival among Lusitanian national heroes

António Dinis da Cruz e Silva, member of Arcádia Lusitana, the literary academy he helped to found, introduced the Pindaric ode to the Portuguese literature of the neoclassical period (18th century). This poet imitates the triadic form and the mythological nature of Pindar’s encomiastic poetry, in order to celebrate the deeds of reputed historical figures from the national context, such as sailors, captains, politicians, and even the king himself. As in Pindar’s poetry, the mythological excursus holds an important part in Cruz e Silva’s Pindaric poetry. Winners of athletic games are acclaimed through allusion to the ancient heroes. Likewise, the heroes of the Portuguese history see themselves turned into immortals, since their deeds are reported as comparatively greater than those of Homeric warriors. Among the 44 Cruz e Silva’s Pindaric odes, 18 rewrite the myth of the Trojan War, from its beginnings with Eris (Odes I-II) to its outcome with the imperishable fame of the most conspicuous Homeric fighters (Ode XLII). These 18 compositions (re)tell, in a neoclassical style, the main scenes and themes of the Iliad and Odyssey, alluding directly to their heroes’ deeds. Achilles’ wrath and Hector’s death are topics repeatedly brought up in Cruz e Silva’s Pindaric poetry as models of courage and patriotism for national heroes. This chapter offers a discussion of Cruz e Silva’s neoclassical representation of the Trojan War. To this effect, an interdisciplinary approach is adopted, showing how the Portuguese poet handles the mythological material from Homer and Pindar. In this way, he initiated in 18th-century Portuguese literature a new literary genre, the Pindaric ode. By dealing with Poetry and History, Cruz e Silva perpetuated the life and fame of national heroes long after their deaths.

L'école de la chasse aux chiens courants / par Le Verrier de la Conterie ; Illustré de huit estampes de Bidinger, de bandeaux d'après Routar et des 27 figures techniques des éditions anciennes

Collection : Les maîtres de la vénerie ; ̊ 5