Self biasing

There are two ways to look at this circuit One is that this is a self-biasing circuit for a BJT amplifier. If this were an amplifier, the load would most likely be a resistor. (The term "self-bias means that the goal of the circuit is to make the collector current independent of device parameters such as Hfe and Vbe.). The second way to look at the circuit is that as far as the load is concerned, Ql, Rl, R2, and R3 form a current source that is, the current through the load is determined by Ql. Rl, R2, and R3. If this circuit were designed as a current source for the load, we could view the circuit as ... 

This efifect of unbalanced electrode surface area is often neglected under the shadow of the self-biasing effect. It is considered that the unbalanced electrode area is the dominant factor that influences the deposition in luminous gas phase, of which the majority of reactive species are neutral. If a small-diameter rod is inserted to the center of the basketlike tumbler as the hot electrode, an extremely high deposition of black carbonaceous film occurs to the rod, and virtually no deposition occurs to the small-size substrates placed in the basket due to the unbalanced electrode surface effect. The extent of the unbalanced electrode effect is dependent to some extent on the nature of monomer. The monomers that deposit easily by LCVD show a pronounced effect and hence cannot be deposited on the substrate. 

The negatively self-biased substrate surface is bombarded with ions which are generated in the discharge (C (H and noble gas ions if noble gases are added). However, not only the C H ions introduce carbon into the film. Comparing the calculated mass deposition rates of major ions (CHj for CH4 gas and C H as well as C6H5 for CsH precursor) with the experimentally determined deposition rates Catherine and Couderc [6] found clear discrepancies in the correlations between rate and RF power and between rate and pressure. In order to overcome these, the adsorption of activated species and their incorporation into the growing film must be taken into account additionally to explain the experimental data. 

Data sheet INA- 12063 1.5 GHz Low Noise Self-Biased Transistor Amplifier, Agilent Technologies, www.semiconductor.agilent.com... 

Fig. 9.9 Illustration of a self-biased photoelectrochemical pn-junction diode (a) and the corresponding photocurrent produced from the device (b). Reproduced with permission from [47], Copyright 2008 Americal Chemical Society.

Mor, G.K., Varghese, O.K., Wilke, R.H.T., Sharma, S., Shankar, K., Latempa, T.J., Choi, K.-S., Grimes, C.A. P-type Cu-Ti-O nanotube arrays and their use in self-biased heterojunction photoelectrochemical diodes for hydrogtai generation. Nano Lett. 8,1906-1911 (2008)... 

Xu Yuhuan, Chen C.J., Xu R., Mackenzie J.D. The self-biased heterojunction effect of ferroelectric thin film on silicon substrate. J. Appl. Phys. 1990 67 2985-2991 Xu Yuhuan, Chen C.J., Xu R., Mackenzie J.D. Ferroelectric thin films on silicon and fused silica substrates by sol-gel process. Mat. Res. Soc. Symp. Proc. 1990 200 13-18 Xu Yuhuan, Chen C.J., Xu R., Mackenzie J.D. Ferroelectric Sro.6Bao.4Nb206 thin films by sol-gel process electrical and optical properties. Phys. Rev. B 1991 44 35 1 Xu Yuhuan. Ferroelectric Materials and Their Applications. Amsterdam, London, New York, Tokyo North-Holland 1991... 

Sessler GM, West JE (1962) Self-biased condenser microphone with high capacitance. J Acoust Soc Am34(ll) 1787-1788... 

Fig. 4 An amplifier with a fully differential and self-biased OTA...

Chae M, Kim J, Liu W (2008) FuUy-differential self-biased bio-potential amplifier. Electron Lett 44 1390-1391. 

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