摘要:

A gallium arsenide diode structure is simulated using a particle-mesh computer model. The model incorporates two dimensions in configuration space, and three dimensions ink-space, with a full description of the material scattering cross-section, which is implemented using Monte-Carlo techniques. Detailed information about electric field and valley population profiles is presented for both dipole domain, and l.s.a. modes of operation. Comparison is made with the widely differing previous theoretical results.

DOI:10.1049/ij-ssed.1977.0012

出版商:IEE    

年代:1977

数据来源: IET

摘要:

A gallium arsenide planar field-effect transistor (f.e.t.) structure is simulated using a particle-mesh computer model. The model incorporates two dimensions in configuration space and three dimensions ink-space; with a full description of the material scattering cross-section which is implemented using Monte-Carlo techniques. The f.e.t. static characteristic has been calculated together with the lumped equivalent-circuit paramters. A comparison is made between devices with and without substrate. Detailed information about electrostatic potential and valley population profiles is presented for the first time. Cole-Cole plots of complex output impedance are used in determining device frequency response.

DOI:10.1049/ij-ssed.1977.0013

出版商:IEE    

年代:1977

数据来源: IET

摘要:

The drift velocity and longitudinal diffusion coefficient have been obtained for electrons from measurements of the transit time of a pulsed electron swarm across a uniform electric field gap. Values have been obtained for electrons in nitrogen, carbon monoxide, carbon dioxide and hydrogen for high values ofE/N(the ratio of electric field to gas number density) in the range 28 ≤E/N≤ 706 Td (1 Td = 10−21Vm2)

DOI:10.1049/ij-ssed.1977.0014

出版商:IEE    

年代:1977

数据来源: IET

摘要:

Josephson junctions using Dayem bridges made from unusually thin films have been operated as mixers. The thickness of the film was made small to increase the r.f. impedance of the device and so to improve r.f. matching, but such thin films often fail to act as Josephson junctions because of surface roughness. In the device reported here, attempts were made to obtain specular reflection of the electron wave functions from the surface. Our devices behaved as good Josephson junctions and gave an internal mixing efficiency of 4.5% at 32 GHz.

DOI:10.1049/ij-ssed.1977.0015

出版商:IEE    

年代:1977

数据来源: IET

摘要:

Multitapped c.c.d. analogue delay lines have been produced with the floating-gate, reset-sensing technique. Although the efficacy of the approach has been demonstrated, no comprehensive design procedure exists to enable systematic device design. Because the c.c.d. and its associated tapping circuitry is an active structure, the operational parameter relationships are extremely complex and dependent on many physical effects. Some of these individual processes have been previously associated with a particular operating parameter, but, usually, for a nontapped device configuration. This paper summarises the basic performance limiting processes of floating-gate tapped c.c.d. delay lines, and presents a quantitative basis for designs and also for further analytical studies. In particular, 3-phase surface-channel devices are considered, although the analyses may be extended to other c.c.d. formations. The equations presented are related to a simple design example based upon a specification achievable in practical devices.

DOI:10.1049/ij-ssed.1977.0016

出版商:IEE    

年代:1977

数据来源: IET

摘要:

A new method is presented for the determination of the large-signal negative resistance of baritt diodes. The simplicity is emphasised in terms of the ususal current/voltage characteristic measurements required. The diodes can thus be characterised, under actual operation conditions, in a microwave circuit, with the help of the present method.

DOI:10.1049/ij-ssed.1977.0017

出版商:IEE    

年代:1977

数据来源: IET