Variable capacity semiconductor and frequency multiplier circuit - is grown as series of diodes spaced by N-type layers and uses gallium:arsenide as implantation substance

摘要

The variable frequency semiconductor is esp. for use with high power frequency multipliers. The semiconductor element minimises parasitic effects and is based on a group of junction diodes connected electrically in series. The group is grown as a series of 'P' and 'N' layers each diode being separated from its neighbour by an 'N' layer. Growth may be by vapour phase, molecular jet, ion implantation etc and is pref. based on gallium arsenide. The spacing 'N' layer prevents any transistor effects due to the (P+)N+(P+)N+ structure and the choice of gallium arsenide ensures low series resistance, uniformity of structure and absence of diffusion parasitic effects. The element (131) is placed across the primary of a transformer fed by the incoming frequency, the secondary circuit (133) being tuned to a frequency greater than that of the input.